Inorganics doi: 10.3390/inorganics14060168

Authors: Nikita S. Aksenin Yury I. Kuzin Mikhail S. Bukharov Alexander A. Rodionov Valery G. Shtyrlin Nikita Yu. Serov

The redox behavior of nickel complexes with sulfur-containing ligands remains of considerable interest due to their significant value in coordination chemistry, catalysis, and bioorganic modeling. In this context, it is important to investigate how aqueous media and acid–base equilibria influence the stability and transformation pathways of such complexes. In this work, the electrochemical behavior of nickel complexes with phosphorylated dithiocarbamate was studied using cyclic voltammetry at various scan rates and pH values. Compared to similar systems in organic solvents, the complexes exhibited additional oxidation and reduction signals, indicating coupled chemical steps. The pH dependence of these peaks confirmed the role of hydroxo groups in the oxidation processes. Varying the scan rate revealed competition between ligand exchange pathways. At low and moderate scan rates, tris-dithiocarbamate nickel(III/IV) complexes are formed, whereas at higher scan rates, hydroxo-containing compounds make a greater contribution. Based on the experimental results and standard redox potentials derived from quantum chemical calculation data, a general scheme for the resulting electrochemical processes was proposed. The results demonstrate the key role of aqueous media and pH in regulating the redox process of nickel complexes with phosphorylated dithiocarbamate.

Inorganics doi: 10.3390/inorganics14060167

Authors: Vesna Đorđević Zoran Ristić Anđela Rajčić Ljubica Đačanin Far Mina Medić Željka Antić Miroslav D. Dramićanin

Temperature-dependent luminescence of Pr3+-doped materials was investigated using both conventional luminescence intensity ratio (LIR) and principal component analysis (PCA)-based thermometry. Three host matrices with distinct structural properties, LiLaP4O12, YNbO4, and Y2O3, were selected to evaluate the influence of crystal structure on thermometric performance. Temperature-resolved emission spectra recorded over the 103–523 K (−170 to 250 °C) range were analyzed using both approaches, with the first principal component (PC1) serving as a thermometric parameter in the PCA. The results show that crystal symmetry and site multiplicity strongly influence the temperature-dependent spectral evolution and, consequently, the thermometric response. LiLaP4O12 exhibits stable and well-defined spectral evolution, resulting in balanced thermometric accuracy and resolution. YNbO4 shows enhanced sensitivity to temperature variations due to increased spectral complexity and stronger crystal-field effects, leading to improved resolution but increased calibration uncertainty. In contrast, Y2O3 exhibits reduced thermometric performance due to overlapping emissions from multiple crystallographically inequivalent sites with distinct thermal responses. Compared to LIR, PCA provides improved thermometric figures of merit, particularly in systems with complex and strongly overlapping emission bands, demonstrating the potential of full-spectrum analysis in luminescence thermometry.

Inorganics doi: 10.3390/inorganics14060166

Authors: Pooloun Lee Il-Ho Kim

Wittichenite (Cu3BiS3) was synthesized by mechanical alloying (MA) followed by hot pressing (HP), and its phase evolution, thermal stability, charge transport behavior, and thermoelectric performance were systematically examined. X-ray diffraction analysis of the MA powders revealed broadened diffraction peaks, indicating reduced crystallinity and refined crystallite size. After HP consolidation, a well-defined single-phase orthorhombic wittichenite structure was obtained. These results demonstrate that the mechanically induced solid-state synthesis was effectively initiated during MA and subsequently completed through crystallization, defect relaxation, and densification during HP. The MA–HP processed specimens exhibited high relative densities of 94–98% of the theoretical value and a homogeneous microstructure without detectable compositional segregation or grain-boundary enrichment, confirming the formation of a structurally and chemically stable single-phase bulk material. Thermal analysis identified a reversible polymorphic phase transition from P212121 to Pnma at low temperature, followed by structural relaxation and the onset of partial decomposition at higher temperatures, indicating that Cu3BiS3 retains structural integrity below 700 K, which defines the relevant operating window for thermoelectric evaluation. The samples exhibited p-type semiconducting behavior, with electrical conductivity increasing with temperature due to thermally activated hole transport and showing an additional enhancement across the structural transition region. The Seebeck coefficient remained positive over the entire temperature range and decreased gradually with increasing temperature, consistent with semiconductor transport characteristics. The thermal conductivity remained low at 0.30–0.38 W·m−1·K−1, with a negligible electronic contribution, confirming that heat transport is dominated by lattice phonon scattering. As a result of the combined increase in electrical conductivity and intrinsically low thermal conductivity, the dimensionless figure of merit (ZT) increased continuously with temperature and reached 0.17 at 673 K. These results demonstrate that the MA–HP route provides an effective and scalable strategy for producing phase-pure Cu3BiS3 with controlled microstructure and reproducible thermoelectric performance.

Inorganics doi: 10.3390/inorganics14060165

Authors: Sai Anvesh Bezawada Cody D. Amann Navya Reddy Sattineni Eike B. Bauer

Ferrocenium-catalyzed transformations provide a practical and sustainable approach to propargylic substitution reactions. Herein, we investigate the ring-opening of cyclopropyl-substituted propargylic alcohols with alcohol nucleophiles, catalyzed by ferrocenium tetrafluoroborate ([FeCp2][BF4]) to afford synthetically valuable enyne ethers. Mechanistic studies using GC and NMR spectroscopy reveal that the reaction proceeds via initial formation of a ring-closed propargylic ether intermediate, which subsequently undergoes ring opening to the enyne ether. Experimental evidence supports a carbocationic pathway in which the ferrocenium cation promotes ionization to a stabilized cyclopropyl ether intermediate, followed by intramolecular, ferrocenium-assisted cyclopropyl ring opening to the enyne product. Reaction rates and product distributions are strongly influenced by temperature and solvent polarity, with polar solvents and elevated temperatures favoring ring opening. At room temperature, the ring-closed substitution product predominates, whereas efficient formation of enynes occurs at 65 °C. The reaction progresses faster in a polar solvent, indicating an ionic mechanism. Studies employing substrates containing substituted cyclopropyl rings demonstrated pronounced regioselectivity during nucleophilic ring opening with alcohols, with preferential cleavage of the bond between the two substituted carbon atoms. This selectivity is consistent with partial positive-charge stabilization in the transition state. The corresponding enyne ether products were isolated in 98–31% isolated yields, in most cases as a single regio- and E/Z stereoisomer (5 h at 45 °C, 5 mol% [FeCp2][BF4] catalyst load, six equivalents alcohol nucleophile). The ferrocenium-catalyzed cyclopropyl ring opening establishes a convenient method for accessing enyne motifs, which are important structural units in organic synthesis and medicinal chemistry.

Inorganics doi: 10.3390/inorganics14060164

Authors: Ze Jiang Yangyang Yu Yin Wang

Organic–inorganic hybrid perovskites (OIHPs) have been widely used in fields such as solar cells, photodetectors, and light-emitting diodes due to their simple preparation by solution methods and excellent optoelectronic properties. In recent years, numerous scholars have delved deeply into the magneto-optical properties of perovskites and explored their potential applications in the magneto-optical field. Herein, we present the Faraday rotation characteristics of formamidinium lead bromide (Fabri3) single crystals within the visible spectrum range. Firstly, FAPbBr3 single crystals with high transparency and a size of 5.5 × 5.6 × 2 mm3 were prepared using the modified inverse temperature crystallization (MITC) method. The experimental results showed that the Verdet constant of FAPbBr3 single crystal at 565 nm was up to 531.6 rad/(T·m). Furthermore, the FAPbBr3 single crystal showed similar or an even higher Verdet constant when compared with the mature magneto-optical material TGG single crystal commonly used in the industry. The thermal simulation results of the FAPbBr3 single crystal show low temperature dependence which achieves about 90% isolation transparency with a magnetic field of 0.35 T for 625 nm. This study demonstrates the outstanding Faraday rotation properties of FAPbBr3 single crystals, thereby offering promising prospects for the development of perovskite materials in non-reciprocal devices such as optical isolators and optical circulators.

Inorganics doi: 10.3390/inorganics14060163

Authors: Shuo Yan Qing-Xu Fan Jun-Peng Liu Fen-Lian Wang Yu-Ji Gao

The selective photocatalytic oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) into high-value 2,5-diformylfuran (DFF) under green conditions is a promising route toward carbon neutrality. However, achieving high efficiency and selectivity in pure water remains challenging due to limited oxygen solubility and nonselective radical reactions. In this study, a series of amorphous MoS3-modified Zn3In2S6 nanoflowers (x%MS/ZIS) with varying MoS3 loadings were successfully synthesized via a one-step hydrothermal method and served as the photocatalysts for the highly selective oxidation of HMF to DFF. The incorporation of MoS3 significantly enhances visible-light absorption, promotes efficient separation of photogenerated carriers, and accelerates surface reaction kinetics. Under visible light irradiation, the optimized 2.4%MS/ZIS catalyst achieves 64.7% HMF conversion and 89.5% DFF selectivity in pure water within 6 h, ~39-fold enhancement in DFF yield compared to pristine Zn3In2S6. Radical scavenging experiments and electron paramagnetic resonance analyses suggest that superoxide radicals (·O2−) and photogenerated holes are the main reactive oxygen species governing the selective oxidation, while the absence of ·OH radicals suppresses overoxidation. This study demonstrates a viable and green strategy for the valorization of biomass platform molecules through visible-light-driven photocatalysis in pure water.

Inorganics doi: 10.3390/inorganics14060162

Authors: Mutaz Salih Soad S. Alzahrani Tarig G. Ibrahim Mohamed R. Elamin Naif Alarifi Ahmed A. Alhadi Babiker Y. Abdulkhair

This study investigated the impact of cobalt/nickel-silicate loadings on graphitic carbon nitride at 10% and 20% doses, designated (CoNiSi-10) and (CoNiSi-20), for the removal of ciprofloxacin (CPF), a hazardous, bioaccumulative antibiotic. The synthesized composites were characterized in detail using SEM, EDX, TEM, N2 adsorption–desorption, XRD, and FTIR techniques. The CoNiSi-10 and CoNiSi-20 exhibited CPF qt values of 64 and 107 mg g−1, respectively, which were consistent with the surface area results. Adsorption kinetics indicated that CPF uptake on CoNiSi-10 and CoNiSi-20 fitted the Lagergren model, with the liquid-film and intraparticle-diffusion mechanisms co-governing CPF sorption. The isotherm investigations indicated CPF adsorption on CoNiSi-10 and CoNiSi-20 aligned with the Langmuir model, suggesting a homogeneous surface, while the Dubinin-Radushkevich results primarily indicated physisorption-based CPF removal. The thermodynamic analyses supported the physisorption outcome and indicated that CPF sorption onto CoNiSi-10 and CoNiSi-20 was endothermic. A five-cycle reusability test yielded average efficiencies of 94% and 96% for CoNiSi-10 and CoNiSi-20, respectively, and an after-sorption analysis indicated their stability and robustness. The ease of synthesis and excellent sorption performance may nominate CoNiSi-10 and CoNiSi-20 as promising adsorbents for treating pharmaceutically contaminated wastewater.

Inorganics doi: 10.3390/inorganics14060161

Authors: Yufei Yue Honglong Ning Xuecong Fang Dongxiang Luo Chi Yuan Haitao Zhu Xu Zhou Xiaojie Li Weiguang Xie Rihui Yao Junbiao Peng

Flexible oxide electronics require dielectric layers that combine low-temperature processability, low leakage current, high capacitance density, and mechanical reliability. In this work, we prepared ZrAlOx-PVP hybrid dielectric films through a low-temperature self-combustion solution process at 180 °C and systematically investigated the effect of PVP doping (0–2 wt%). The results show that PVP promotes the formation of M-O-C related bonding environments, suggesting the construction of an organic–inorganic crosslinked structure. Moderate PVP incorporation effectively suppresses leakage pathways, whereas excessive PVP induces polymer aggregation and trap-assisted conduction. Among all samples, the film on flexible PI (polyimide) with a PVP doping concentration of 0.5 wt% exhibits the best overall performance, with a leakage current as low as 1.89 × 10−8 A/cm2 at 1 MV/cm, a dielectric constant of 8.88. After static bending at a radius of 20 mm, the film maintains stable dielectric behavior, indicating improved stress tolerance. Flexible IGZO TFT fabricated with the optimized dielectric shows a mobility of 11.84 cm2 V−1 s−1, a threshold voltage of 0.48 V, and a subthreshold swing of 0.24 V dec−1 before bending. This work demonstrates that moderate PVP crosslinking provides an effective balance between defect suppression and stress relaxation, offering a practical interface-engineering strategy for low-temperature flexible high-k dielectrics.

Inorganics doi: 10.3390/inorganics14060160

Authors: Stefano Bellucci

Carbon/inorganic hybrid composites have evolved from filler-reinforced materials into design platforms for coupled electromagnetic, thermal, sensing, environmental, protective and energy-related functions. Their distinctive value lies in the possibility of combining a conductive, polarizable or porous carbon phase with an inorganic phase that contributes dielectric, magnetic, catalytic, ionic, thermally conductive or barrier behavior. This review examines carbon/inorganic hybrid multifunctional composites from the viewpoint of structure–property relationships, with emphasis on interfacial design, percolation, anisotropy, hierarchical architecture, processing and metrology. Selected graphitic composite studies are discussed as case studies for broadband dielectric spectroscopy, microwave shielding, high-frequency contact metrology, thermal diffusivity analysis and impedance-monitored graphene filters; these case studies are integrated with the broader international literature on CNT and graphene polymer composites, MXene films and foams, graphene/metal oxide photocatalysts, boron nitride/carbon thermal networks, biochar–graphene adsorbents, smart coatings, sensors, supercapacitors and water remediation systems. The central argument is that credible multifunctionality requires more than measuring several properties on the same material. It requires simultaneous or service-relevant co-optimization under constraints of thickness, density, processability, aging, humidity, corrosive media, regeneration, toxicity, economic feasibility and scalable fabrication. The review concludes with design rules and reporting recommendations intended to help move the field from impressive property demonstrations toward application-ready hybrid material systems.

Inorganics doi: 10.3390/inorganics14060159

Authors: Naif Abdullah R. Almalki

This study reports the plant-mediated synthesis of copper-oxide-decorated magnetic iron oxide composite (CuO@Fe3O4) nanoparticles using Dolomiaea costus extract and their application as nanocarriers for β-galactosidase immobilization. The fabricated nanocomposite exhibited favorable physicochemical properties, achieving an immobilization efficiency of 83%, with enhanced thermal and pH tolerance compared to the free enzyme. Kinetic analysis revealed a modest increase in Km and a 31% decrease in Vmax after immobilization, while maintaining 69% of the catalytic activity, confirming the system’s suitability for industrial lactose hydrolysis. Reusability and storage tests showed 79% retained activity after five cycles and 77% after 60 days at 4 °C. In milk hydrolysis, the immobilized enzyme achieved 77% conversion within 3 h, following pseudo-first-order kinetics. Biocompatibility was evaluated using HepG2 cells via the MTT assay. BDH, MDH, and ABC maintained high cell viability across the tested dilution range of 25–100% (v/v), indicating no detectable cytotoxic effect under the experimental conditions, whereas cisplatin showed marked cytotoxicity with an IC50 of 14.98 µg/mL. These findings demonstrate that the green-synthesized CuO@Fe3O4 support provides a safe, reusable, and magnetically recoverable platform for β-galactosidase immobilization, offering a promising sustainable strategy for producing lactose-free dairy products.

Inorganics doi: 10.3390/inorganics14060158

Authors: Yanina Mariella Dreer Kim-Isabelle Mehnert-Birk Ivan Shestov Deven P. Estes Rainer Niewa

The study investigates Co2+/M4+ (Sn, Zr, Hf)-substituted M-type barium ferrites to understand phase formation, structural evolution and magnetic behavior. Ferrites with the general composition BaFe12−x−yCoxMyO19 were synthesized via sodium carbonate flux and analyzed using powder and single-crystal X-ray diffraction, wavelength dispersive X-ray spectroscopy, X-ray absorption spectroscopy and magnetic measurements. Structural analysis showed increasing lattice parameters with increasing degree of substitution, confirming incorporation of the substituting tetravalent metals. Differing maximum substitution levels were determined for the different systems, with wavelength dispersive X-ray spectroscopy providing the most reliable compositional data. A slight excess of the tetravalent metals Sn4+, Zr4+ and Hf4+ relative to Co2+ was frequently observed. X-ray absorption spectroscopy and wavelength dispersive X-ray spectroscopy analyses indicated negligible Fe2+ formation and no clear trends for formation of vacancies. Site occupancy analysis assigned tetravalent cations primarily to the Fe(4) site (4f2), with evidence that cobalt partially occupies the Fe(3) site (4f1). Magnetic measurements revealed decreasing saturation magnetization, remanence and coercivity at room temperature with increasing substitution level, while low-temperature measurements showed enhanced remanence and coercivity.

Inorganics doi: 10.3390/inorganics14060157

Authors: Mariely Loeza-Poot Inés Riech Ricardo Mis-Fernández Eduardo Flores David Meneses-Rodríguez Eric Hernández-Rodríguez

Solar cell efficiency depends on both photogeneration and charge collection, with the active layer playing a key role in these processes. In organic solar cells (OSCs), where power conversion efficiency (PCE) remains relatively low, understanding the influence of active layer and metal contact thickness on device performance is essential. In this work, we investigate the effect of P3HT:PCBM and Ag thickness on OSC performance by analyzing the evolution of electrical parameters obtained from J-V measurements over five weeks, with particular attention given to resistance-related degradation behavior. The analyzed OSCs had a cell structure composed of Ag/P3HT:PCBM/TiO2/ITO/glass, and each material was corroborated by XRD and Raman spectroscopy. The thickness of P3HT:PCBM was modulated by varying the number of spin-coated layers from 1 to 3 (ranging from 75 to 160 nm). This variation increases light absorption, as demonstrated by the optical transmittance spectra. However, device degradation became evident after the third week of fabrication, mainly due to an increase in series resistance, which adversely affected the open-circuit voltage (VOC), fill factor (FF), and overall device efficiency. The best performance was obtained for devices fabricated with two P3HT:PCBM layers and 18 mg of Ag, achieving a maximum PCE of 0.5%.

Inorganics doi: 10.3390/inorganics14060156

Authors: Kaiyuan Chen Danning Huang Xiande Zheng Jinwei Qu Xiuyun Lei Senentxu Lanceros-Méndez Liang Fang Feifei Han Liaoting Pan Qi Zhang Laijun Liu

B-site ordering of Li-modified Pb0.95Li0.05(Yb1/2Nb1/2)O3 (PLYN) ceramics can be changed by duration during sintering. In this paper, the conventional solid-state reaction method was employed to prepare antiferroelectric perovskite Li-substituted PLYN ceramics. Crystal structure evolution dependence of sintering time was investigated using X-ray diffraction (XRD), Raman spectroscopy, and dielectric response. Two dielectric anomalies responses, attributed to the transition from B-site order to disorder and antiferroelectric-paraelectric phase transition depend on B-site ordering. The high-temperature dielectric relaxation associated with charged carries (oxygen-vacancy hopping) was characterized by isothermal electric modulus and universal dielectric response. Impedance spectroscopy was used to uncover the relationship between defect type and the oxygen partial pressure (pO2) dependence on sintering time in PLYN systems. These findings provide new insights into the interplay among B-site ordered phase structure, dielectric response, and defect types.

Inorganics doi: 10.3390/inorganics14060155

Authors: Tommaso Lorenzon Alessia Schiavo Anita Piccoli Nicolò Perin Lorenzo Rodighiero Nicola Demitri Giovanni Tonon Fabiano Visentin Flavio Rizzolio Isabella Caligiuri Martina Scianna Catherine S. J. Cazin Steven P. Nolan Thomas Scattolin

Azolium-derived metallates are well-established intermediates in metal–N-heterocyclic carbene chemistry; however, their potential as standalone therapeutic agents remains largely unexplored. Herein, we report the first systematic biological investigation of a diverse family of Au(I), Cu(I), Pt(II), Pd(II), and Ru(II) metallates paired with functionalized azolium cations. The complexes were synthesized quantitatively through a simple, atom-economical, and purification-free protocol under aerobic conditions in technical-grade green solvents. Structural characterization by multinuclear NMR spectroscopy and single-crystal X-ray diffraction confirmed metallate formation and enabled the first isolation and crystallographic characterization of unprecedented azolium-derived ruthenates. The antiproliferative activity of the complexes was evaluated against cisplatin-sensitive (A2780) and cisplatin-resistant (A2780cis) ovarian cancer cell lines, alongside non-cancerous MRC-5 fibroblasts. Backbone-functionalized derivatives emerged as the most potent compounds, displaying activities comparable or superior to cisplatin in A2780 cells and up to 1000-fold higher potency in the resistant A2780cis model. Notably, unlike cisplatin, the metallates retained nearly unchanged IC50 values across both ovarian cancer lines, strongly suggesting resistance-evasive mechanisms of action. While benzylazido- and methyl guanosine-derived complexes generally exhibited lower overall potency, several members retained significant activity in resistant cells while showing markedly reduced toxicity toward normal fibroblasts, highlighting promising selectivity profiles. Ethoxide-functionalized derivatives and platinum-based metallates combined pronounced anticancer activity with favourable therapeutic windows. Overall, this work establishes azolium-derived metallates as a previously overlooked class of metal-based anticancer agents combining exceptional synthetic accessibility, broad structural tunability, and remarkable activity against platinum-resistant ovarian cancer.

Inorganics doi: 10.3390/inorganics14060154

Authors: Bin-Bin Chen

Luminescent materials have garnered widespread research interest due to their excellent photophysical properties, which have been extensively applied in diverse fields such as chemo-/biosensing, cellular imaging, cancer therapy, and optoelectronic devices [...]

Inorganics doi: 10.3390/inorganics14060153

Authors: Mahboubeh Dolatyari Ali Rostami Axel Klein

The field of infrared (IR) photodetection is undergoing rapid development through the emergence of solution-processable nanoparticle (NP)-based materials and fabrication strategies. This review critically examines recent advances in fabrication approaches for NP-based IR detectors, emphasizing the relationship between synthesis, surface engineering, deposition processes, and device architecture in determining detector performance. Representative material platforms are discussed, including colloidal quantum dots (CQDs) such as PbS and HgTe, which enable tunable operation from the near-infrared (NIR) and short-wave infrared (SWIR) to selected mid-wave (MWIR), long-wave (LWIR), and emerging very-long-wave infrared (VLWIR) regimes depending on material composition and operating conditions. Further platforms including plasmonic metal NPs, black phosphorus, and topological nanomaterials are evaluated for their unique mechanisms of optical enhancement and broadband response. Fabrication approaches including continuous-flow synthesis, ligand exchange, blade coating, inkjet printing, electrophoretic deposition, and other scalable solution-processing methods are analyzed with respect to their influence on film quality, charge transport, interface engineering, and integration compatibility. The review further compares major device architectures, including photoconductors, photodiodes, plasmonic absorbers, and phototransistors, using key performance metrics such as specific detectivity (D*), responsivity (R), response speed, and operating temperature, while emphasizing the importance of measurement conditions in cross-platform comparisons. Critical challenges including dark-current generation, 1/f noise, transport limitations associated with ligand chemistry, environmental instability of narrow-bandgap materials, manufacturability constraints, and toxicity considerations are also discussed. Emerging directions such as neuromorphic sensing, CMOS-compatible integration, and sustainable lead-free nanomaterials are highlighted. By linking nanoscale material design and fabrication processes to device-level performance, this review provides a framework for advancing NP-based IR technologies toward scalable and application-relevant sensing systems.

Inorganics doi: 10.3390/inorganics14060152

Authors: Alondra Villegas-Menares Max Bayas María Herrera-Maldonado Sebastián Villaroel-Sierra Claudio Barrientos Antonio Galdámez Iván A. González Alan R. Cabrera

Three new heteroleptic copper(I) complexes of the form [Cu(N,N)(XantPhos)]PF6 were synthesized and characterized, where N,N refers to phenyl-substituted imidazo[4,5-f][1,10]phenanthroline. All complexes were obtained as yellow powders in yields ranging 82–95% and were fully characterized by NMR spectroscopy, FT-IR, and mass spectrometry. The complexes were also redox-optically characterized. Their absorption profiles display a lower-energy metal-to-ligand charge-transfer (MLCT) band at approximately 412 nm. In solution, weak dual emission is observed, combining ligand-centered and MLCT contributions, with oxygen-dependent quenching supporting the presence of triplet character in the latter. Temperature- and solvent-dependent studies reveal thermally coupled emissive states, in which a relaxed 3MLCT state dominates at low temperatures. In the solid state, intense orange-to-red emission arises from restricted molecular motion and stabilized 3MLCT states, with C3 showing the highest efficiency. Additionally, aggregation-induced emission (AIE) is observed in solvent mixtures. These results suggest that remote substitution can influence the excited-state dynamics and aggregation-driven emission in Cu(I) complexes.

Inorganics doi: 10.3390/inorganics14060151

Authors: Peng Xing Wenjun Fang Ying Liu Riqin Shan Hui Zhang Junming Wu Tao Fang Yong Huang

This study examines technological change in Longquan celadon from the Dayao kiln-site area by asking three related questions: how body and glaze compositions changed from the Southern Song to the Yuan and Ming periods; how these compositional changes relate to glaze color and microstructure; and how firing-temperature data from representative ceramic bodies help to clarify firing practice within the sampled kiln sequence. Twenty celadon sherds from Jincun Dayao Bentou, Dayao Shantoucheng, Dayao Mulianyan, and Zhulongcun Panchuangkou were analyzed by energy-dispersive X-ray fluorescence spectroscopy (EDXRF), CIE L*a*b* color measurement, scanning electron microscopy (SEM), and high-temperature dilatometry. The results show that the Yuan-associated bodies in this sampled assemblage contain higher Al2O3 and K2O and lower SiO2 than the Southern Song and Ming groups, indicating a strengthened aluminum- and potassium-rich body system. Glaze chemistry records a staged rebalancing of the flux system: from the high-calcium condition represented by Northern Song reference glazes, through a transitional Southern Song state, to a stronger calcium-alkali character in the Yuan period, followed by a partial return toward a more calcium-rich recipe in the Ming period. Color measurement indicates that the Yuan samples generally have lower b* values, reflecting a reduced yellow component and a more bluish-green tendency; their relatively lower L* values also correspond to a darker glaze appearance, although this difference is less pronounced than that observed for b*. SEM observations of four representative cross-sections show glass-dominated glazes, anorthite-bearing body–glaze interlayers, and mullite-bearing bodies; the two Yuan representatives have thicker glaze layers and local phase separation, suggesting that their darker and more bluish appearance was produced by the combined effects of glaze chemistry, thickness, and microstructure. Firing-temperature data obtained from high-temperature dilatometry show that the representative samples were fired within a high-temperature range, while the variation between the two Yuan specimens suggests greater flexibility in firing practice during this period. Taken together, the data suggest that Longquan celadon underwent a non-linear technological reorganization, with the Yuan phase forming a key interval of compositional, microstructural, visual, and firing-related reconfiguration.

Inorganics doi: 10.3390/inorganics14060150

Authors: Andrés Suárez-Escobar Ricardo Ríos-Linares Tatiana Santos-Castellanos Andrea Álvarez-Cabrera Felipe Mendoza-Abella Miguel A. Esteso

Potassium-modified titanium dioxide (TiO2–K) was synthesized and evaluated as a heterogeneous photocatalyst for fatty acid methyl ester (FAME) production from palm oil under UV irradiation. The catalyst was characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) analysis, and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM–EDS). Potassium modification preserved the TiO2 crystalline framework while producing marked changes in morphology and a significant decrease in surface area. Photocatalytic transesterification was optimized using a central composite design, evaluating the effects of catalyst loading and the methanol-to-oil molar ratio on FAME yield. The quadratic response surface model adequately described the experimental data and predicted an optimum FAME yield of approximately 98.96% under the evaluated conditions. Kinetic analysis showed that the reaction profile was well described by an apparent pseudo-first-order model, consistent with the use of excess methanol, while the Avrami–Weibull equation provided a flexible empirical representation of the conversion profile. Control experiments confirmed that irradiation and catalyst presence were required for measurable FAME formation. Overall, this study demonstrates the potential of TiO2–K as a photocatalyst for light-assisted biodiesel production and provides an initial framework for process optimization and kinetic interpretation.

Inorganics doi: 10.3390/inorganics14060149

Authors: Dai Cuong Tran Indirajith Palani Heeseo Kim Sangmin Lee Sangho Cho Myung Mo Sung

Semiconducting metal oxides are gaining attention in thermoelectric applications, where performance is evaluated by the figure of merit (ZT), which depends on the power factor (S2σ) and thermal conductivity (κ). However, achieving high ZT values in these materials remains challenging. This study introduces a distinct strategy to enhance thermoelectric performance by infiltrating aluminum-doped zinc oxide (AZO) into poly(methyl methacrylate) (PMMA) films using the vapor-phase infiltration (VPI) technique. The resulting AZO/PMMA hybrid films exhibit a unique composite structure with AZO nanocrystals embedded within an amorphous PMMA matrix. This structure facilitates energy-dependent carrier scattering (the energy filtering effect) at the AZO/PMMA interfaces, thereby enhancing the Seebeck coefficient, while phonon scattering at the interfaces reduces thermal conductivity. By precisely controlling VPI parameters, we achieved a uniform dispersion of AZO nanocrystals within the PMMA matrix. The optimized AZO/PMMA hybrid film demonstrated a power factor of 1306 μW m−1 K−2 and a thermal conductivity of 1.02 W m−1 K−1, resulting in a ZT value of approximately 0.384 at 300 K, which is one of the highest reported for metal oxide thermoelectric materials near room temperature. The successful integration of AZO into the PMMA matrix via VPI opens new pathways for developing high-performance, flexible thermoelectric materials.

Inorganics doi: 10.3390/inorganics14060148

Authors: Peizhuang Wang Lipeng Xu Xiantao Li Renyi Yang Jun Li

At present, lithium lanthanum zirconate (LLZO) is regarded as one of the most promising solid-state electrolyte materials due to its high ionic conductivity (about 10−3 S/cm at room temperature), high chemical stability, and excellent chemical stability toward cathode materials and lithium metal anodes. However, there are several problems, such as poor interface contact with the lithium metal anode resulting in high interface impedance, a high sintering densification temperature (usually >1200 °C), a complex preparation process, and high cost. In recent years, researchers have conducted extensive studies on LLZO and achieved remarkable progress and results. This paper systematically reviews the research progress of LLZO’s structural characteristics, conductive mechanism, preparation methods, improvement strategies, and so on.

Inorganics doi: 10.3390/inorganics14060147

Authors: Seyedehfaranak Hosseinigourajoubi Chris Schade Jacques Huot

In the original publication [...]

Inorganics doi: 10.3390/inorganics14060146

Authors: Myrna Luna-Gutiérrez Erika Azorín-Vega Blanca Ocampo-García Nallely Jiménez-Mancilla Clara Santos-Cuevas Nancy Lara-Almazán Cintya Herrera-García Laura Meléndez-Alafort Guillermina Ferro-Flores

Copper-64 is increasingly recognized for its advantages in positron emission tomography (PET) imaging and theranostic applications due to its favorable half-life, decay profile, and high spatial resolution. This research addresses the need for reliable, high-purity PET radiotracers by developing GMP-grade lyophilized kits for one-step preparation of 64Cu-NOTA-peptides using gelatin as a chelating agent for metallic impurities and NOTA for selective copper binding. The approach was applied to five peptide analogs formulated for fast 64Cu labeling: NOTA-iPSMA, NOTA-TOC, NOTA-iPD-L1, NOTA-iFAP, and NOTA-UBI 29–41, which were preclinically evaluated to enable the precise molecular imaging of cancer and infection. Each multidose kit included 0.5 μmol of the NOTA-peptide and 25 mg of gelatin, labeled with 925 MBq of 64Cu. The radiochemical purity of the 64Cu-NOTA-peptides exceeded 98% (mean 99.2% ± 0.3%) without the need for additional purification. The 64Cu-radiotracers remained stable for at least 24 h at room temperature and showed high stability in human serum. In preclinical studies, saturation-binding assays demonstrated that affinity (Kd) was less than 10 nM in all 64Cu-NOTA-peptides, with tumor-to-lung ratios ranging from 14 to 290 at 2 h post-injection and low liver uptake (2.95% ± 1.36% ID/g). The research demonstrated that these formulations, which include peptides specific to PSMA, SSTR2, PD-L1, FAP, and infection sites, offer excellent in vivo performance and high PET imaging quality in mice with induced tumors or infection sites. The findings support the use of gelatin-NOTA-peptide kits as a standardized and practical solution for producing 64Cu-labeled peptides, facilitating routine clinical PET imaging, and advancing personalized molecular diagnostics.

Inorganics doi: 10.3390/inorganics14060145

Authors: Tao Guo Tomoya Ikuta Chaoyang Li

ZnO nanorods were synthesized on AZO substrates by chemical bath deposition, and were subsequently annealed under an air and vacuum ambient. Both annealing processes could improve the crystallinities of ZnO nanorods. The air-annealed ZnO nanorods showed higher crystallinity and partial reduction of oxygen-vacancy-related defects. The air-annealed ZnO nanorods exhibited a much higher photodegradation efficiency of 70% degradation for methyl red. In addition, as-grown ZnO nanorods were coated with undoped and Al-doped ZnO by mist chemical vapor deposition. Both coated thin layers modified the surface of ZnO nanorods, while the AZO-coated ZnO nanorods showed higher crystallinity and light absorption which resulted in the improvement in the photodegradation rate of methyl red. These findings demonstrate that appropriate annealing treatment and AZO surface engineering for ZnO nanorods are effective approaches for improving crystallinity, which leads to improvement of the photocatalytic efficiency of ZnO-based materials.

Inorganics doi: 10.3390/inorganics14060144

Authors: Hilmi Hisyam Naimin Ruhanita Maelah Hawa Hishamuddin Muhamed Ali Shaikh Abdul Kader Abdul Hameed Mohd Nizam Ab Rahman Amizawati Mohd Amir

Coal has been Malaysia’s primary energy source for electricity generation for the past few decades, resulting in increased greenhouse gas emissions and irreversible environmental damage. Solid Oxide Fuel Cells (SOFCs) have emerged as a viable clean-energy alternative to mitigate these environmental effects. There has been significant emphasis on developing pollution-free technology, with limited attention given to the environmental impact of SOFC. Research and development efforts have primarily focused on the design and technical aspects of SOFC. Prior to the introduction of SOFC to market, quantifying the environmental footprint of SOFC manufacturing is necessary to support a sustainable energy transition. This study conducts a comprehensive Life Cycle Assessment (LCA) of SOFC manufacturing in accordance with ISO 14040 and 14044 standards. The analysis focuses on a planar electrolyte-supported SOFC with a lifespan of 4.57 years, using a functional unit of 1 kWh electrical output. The Environmental Footprint (EF) 3.1 method implemented in GaBi Software was used for the impact assessment. Key environmental impact categories considered in the LCA include Climate Change (CC), Acidification Potential (AP), Eutrophication Potential (EP), Ozone Depletion Potential (ODP), Photochemical Ozone Formation (POF), and Human Toxicity Potential (HTP). The total climate change impact is approximately 19.674 kg CO2 eq./kWh, with the Balance of Plant (BoP) phase contributing 91% of this impact, while the fuel cell stack phase contributes 1.25%. The study identifies key areas for improvement, primarily related to BoP and other high-impact processes, and emphasizes the importance of targeted measures to effectively reduce the environmental impacts associated with SOFC manufacturing.

Inorganics doi: 10.3390/inorganics14060143

Authors: Adel Sayed Orabi Sara Reda Fisal Ibrahim Ahmed Ibrahim Ali W. Christopher Boyd Haitham Kalil Abbas Mamdoh Abbas

Moxifloxacin-based Schiff-base ligands provide a useful platform for tuning the coordination and biological properties of fluoroquinolone derivatives. Here, a moxifloxacin–salicylaldehyde hydrazone ligand (MOX-S) was prepared and coordinated with cobalt(II), nickel(II), copper(II), oxovanadium(IV), and gadolinium(III) ions to obtain a series of metal complexes. Citrate-stabilized gold nanoparticles (AuNPs) were also prepared and functionalized with MOX-S and the Cu(II) complex to evaluate the effect of nanoformulation on biological performance. The compounds were characterized using complementary analytical, spectroscopic, magnetic, thermal, and microscopic techniques. The combined data support 1:2 metal-to-ligand formulations for the complexes and indicate coordination mainly through the azomethine nitrogen and oxygen donor sites of MOX-S. In antimicrobial screening, the activity was strongly metal- and organism-dependent. Cu–MOX-S and VO–MOX-S showed the most pronounced activity against Gram-positive bacteria, with inhibition zones of up to 30 mm, while Cu–MOX-S displayed MIC values of 19.53 and 39.06 µg mL−1 against Bacillus subtilis and Staphylococcus aureus, respectively. Cytotoxicity assays showed that MOX-S was more active than moxifloxacin against MCF-7 and HepG2 cells, while Cu–MOX-S showed enhanced potency, particularly toward HepG2 cells, with an IC50 of 0.98 µM and a selectivity index of 5.97. AuNP formulations further increased the apparent antiproliferative potency in the tested cancer cell lines, giving sub-micromolar IC50 values. Computational analyses, including DFT-based electronic descriptors and molecular docking, provided qualitative support for the experimentally observed coordination and cytotoxicity trends. Overall, metal coordination and AuNP formulations provide complementary strategies for modulating the physicochemical and in vitro biological behavior of this moxifloxacin-derived hydrazone scaffold.

Inorganics doi: 10.3390/inorganics14050142

Authors: Milan Melník Natalia Miklášová Veronika Mikušová Peter Mikuš

Structural parameters for over seventy complexes of the composition Cu(η2-X1×2)(Y3) or Cu(κ2-X1X2)(Y3) were analyzed in this work, being the third of a series of structural studies on three coordinated copper(I) complexes. Bidentate (X1X2) with monodentate (Y3) donor ligands build up distorted trigonal planar coordination spheres around copper(I) atoms. The bidentate ligands (X1X2) create three-, four-, and five-membered metallocyclic rings. The three-membered are: -C1-C2-Cu-C3; -B1=B2-Cu-Cl3; -P≡C2-Cu-C3, -B1-B2-Cu-X3, and B1-C2-Cu-C3. The X1-Cu-X2 angles indicate a total mean value of 44.2°. The four-membered complexes are -H1-B(H2)-H2-Cu-C3; -H1-B(Ph2)-H2-Cu-C3; -O1AlO2-Cu-N3; -O1CeO2-Cu-N3; -S1CP2-Cu-C3; -N1PN2-Cu-C3; -N1PS2-Cu-P3; -N1SiO1-Cu-Cl3; --N1CS2-Cu-C3; -Si1-NSi2-Cu-C3, and O1CO2-Cu-C3, and show a total mean value of the L-Cu-L angles of 71.0°. The five-membered are: -N1-C=C-N2-Cu-Y3 (more common) and N=C-C=N-Cu-C3. In this group, there are also copper(I) complexes in which the central Ns of five-membered metallocycle are “interlocked” in macrocycles. The X1-Cu-X2 angles exhibit an average value of 82.9°. There is a wide variety of monodentate (Y3) ligands in the studied complexes. The mean value of Cu-Y3 elongates with covalent radius (Å) of coordinate atoms in the sequence: 1.846(13) Å (N3, 0.75) < 1.884(21) Å (O3, 0.73) < 1.928(18) Å (C3, 0.77) < 2.126(18) Å (Cl3, 0.99) < 2.140(5) Å (S3, 1.02) < 2.194(4) Å (P3, 1.06) < 2.246(12) Å (Br3, 1.14) < 2.2445(18) Å (I3, 1.33). The data show that angular distortion from regular trigonal geometry grows in the following order: five-, four-, and three-membered.

Inorganics doi: 10.3390/inorganics14050141

Authors: Hasleidy Úsuga-Guerra Milton Rojas John Rojas Lis Manrique-Losada Daniel Ávila-Torres Ricardo A. Torres-Palma Yenny P. Ávila-Torres

Mercury pollution from artisanal and small-scale gold mining remains one of the most persistent environmental threats due to the high toxicity, mobility, and bioaccumulation of Hg(II). In this work, Colombian banana pseudostem waste is valorized into a lignocellulosic carbocatalyst through pyrolysis at 500 °C followed by MnCO3-derived MnOx functionalization, producing a sustainable material for Hg(II) remediation. The transformation of the biomass leads from a fibrous structure (~25 µm) to a pyrolyzed carbon matrix (9.56 µm), and finally to a heterogeneous Mn-modified system with bimodal particle distribution (~25 µm and ~0.85 µm), the latter being associated with highly dispersed MnOx redox-active domains. Structural and textural analyses reveal that Mn incorporation significantly enhances surface properties, increasing the BET surface area from 140.8 to 213 m2 g−1 while reducing pore size to the meso–microporous range (~1.9 nm). Importantly, the material retains intrinsic minerals such as Ca, Mg, K, and Si, which contribute to surface basicity and ion-exchange capacity, supporting additional Hg(II) interaction pathways. Optical and electronic characterization shows a wide band gap semiconductor behavior (≈3.4 eV) and a conduction band position at −0.892 V vs. NHE, sufficiently negative to thermodynamically drive Hg2+ reduction to Hg0 under UV-A irradiation. Hg(II) quantification was validated using a UV–Vis method based on the Hg2+–dipicolinic acid (DPA) complex, confirming stable complex formation with 1:2 stoichiometry (Hg2+:DPA) and high analytical reliability (R2 = 0.948, LOD = 1.85 mg L−1). Photocatalytic experiments demonstrated negligible Hg(II) reduction under UV-A light in the absence of catalyst, whereas the carbon-based materials enabled significant Hg transformation through adsorption-assisted photoinduced electron transfer. Electrochemical analyses (Rct ≈ 11 Ω) confirmed efficient charge transport, while cyclic voltammetry evidenced reversible Mn(IV)/Mn(III)/Mn(II) redox cycling, which sustains electron mediation during photocatalysis. Overall, pristine biochar acts primarily through adsorption driven by oxygenated functional groups and porous structure, whereas Mn-functionalized biochar operates via a synergistic adsorption–photocatalytic mechanism. In this system, MnOx species function as redox-active centers that facilitate electron transfer from the carbon matrix to Hg(II), while the conductive lignocellulosic-derived framework enhances charge mobility. The combination of structural carbon stability, dispersed Mn active sites, and inherent mineral functionality establishes a highly efficient and sustainable carbocatalyst, demonstrating a green and scalable approach for mercury remediation in mining-impacted regions.

Inorganics doi: 10.3390/inorganics14050140

Authors: Alondra Villegas-Menares María Herrera-Maldonado Iván Brito Michelle Palacios Sebastián Muñoz-Farias Mario A. Faundez Alan R. Cabrera

In this study, we report the synthesis and characterization of three Cu(I) complexes bearing functionalized dipyridylamine ligands and DPEphos. Structural analysis confirms a distorted tetrahedral coordination environment around the metal center. Photophysical studies in DMSO show similar absorption profiles (λabs ≈ 341–343 nm) with ligand-centered and MLCT transitions, while emission spans the visible region (λemi = 410–483 nm) and is strongly influenced by ligand substitution, with the CF3 derivative displaying a marked red shift. Emission is insensitive to oxygen and exhibits short lifetimes (τ ≈ 14.9–15.3 ns), suggesting short-lived 1MLCT excited states. Biological evaluation in A375 melanoma cells reveals that all complexes exhibit low-micromolar cytotoxicity under dark conditions (IC50 = 3.33–4.92 μM). Notably, only the CF3-substituted complex shows a significant light-induced enhancement of activity upon irradiation at 390 nm (IC50 = 1.18 μM), indicating photoactivation.

Inorganics doi: 10.3390/inorganics14050139

Authors: Aimé L. Acosta-Soto Laura G. Ceballos-Mendívil Jonathan C. Luque-Ceballos Rody Soto-Rojo Francisco Baldenebro-López Adriana Cruz-Enríquez José J. Campos-Gaxiola Carlos A. Pérez-Rábago Jesús Baldenebro-López

Ultra-high-temperature ceramics (UHTCs) in the Ta–Hf–C ternary system are of significant interest for extreme aerospace and energy applications due to their melting points near 4000 °C. However, their synthesis typically requires extreme temperatures and pressures. This study reports a pectin-assisted low-temperature route for Ta-rich TaxHf1−xC powder synthesis via carbothermal reduction at 1500 °C. The effect of Ta/Hf molar ratios (2.7/1, 0.9/1, and 0.3/1) on phase evolution, crystallinity, and morphology was systematically investigated. FTIR confirmed the successful formation of homogeneous hybrid organic–inorganic precursors through the chelation of metal ions with pectin functional groups. XRD results demonstrated that the Ta-rich composition (Ta/Hf = 2.7/1) promotes the formation of a high-purity (95.87%) cubic solid solution (lattice parameter a = 4.453 Å) with sharp reflections and improved crystallinity. In contrast, Hf-rich samples exhibited incomplete conversion, leaving unreacted HfO2 and Ta2Hf6O17 oxide phases due to the high thermodynamic stability of hafnia. Microstructural analysis revealed quasi-spherical TaxHf1−xC particles with an average size of approximately 123 nm, together with finer residual oxide particles of about 50 nm. Overall, these results demonstrate that pectin-assisted precursor chemistry is an effective strategy for promoting low-temperature carbide formation in Ta-rich TaxHf1−xC compositions.

Inorganics doi: 10.3390/inorganics14050138

Authors: Xing Hu Qinming Liu Chenglin Ding Kuo Yang Bingqi Tian

Thermal runaway (TR) remains a critical bottleneck for the safe application of lithium-ion battery (LIB) in large-scale energy storage systems, arising from the instability of battery materials under high temperatures. This review systematically summarizes materials design strategies to suppress TR, focusing on modifications of cathodes, anodes, separators, and electrolytes. For cathodes, surface coating and bulk doping enhance the structural stability and thermal decomposition temperature of high-Ni materials, while nanoscale engineering and carbon networks improve the electronic conductivity and interfacial stability of LiFePO4 (LFP). For anodes, surface modification of graphite suppresses solid-electrolyte interphase degradation, and nanostructured silicon-based composites mitigate thermal failure caused by volume expansion. Separator functionalization, including ceramic coating, inorganic separators, and thermal shutdown separators, enhances thermo-mechanical stability and enables thermally triggered ion blocking. Flame-retardant electrolytes incorporate phosphorus-based, organosilicon, and halogenated additives that act through combined gas- and condensed-phase mechanisms. The review further discusses challenges in interfacial compatibility, system integration, and trade-offs among multiple performance metrics. Future efforts should focus on integrating intrinsic thermal stability with smart safety functions to achieve both high energy density and inherent safety. This review provides a systematic reference for the design and industrialization of high-safety materials for LIBs.

Inorganics doi: 10.3390/inorganics14050137

Authors: Youqing Wang Tiantian Yang Minghui Liu Xilin Xu Furong Hou Renqianzhuoma Renqianzhuoma Linjuan Yang Xiangyi Guan Huixia Liao Ying Xiang

To clarify the instability behavior of the columnar microstructure in RF magnetron sputtered TiN coatings under compressive loading, experimental characterization and finite element simulation were combined to investigate the microstructural features, mechanical properties, and linear and nonlinear buckling responses of the coating. TiN coatings were deposited on cemented carbide and Si substrates by RF magnetron sputtering using a 99.9% purity TiN target. The surface and cross-sectional morphologies were characterized by field-emission scanning electron microscopy, and the nanohardness and Young’s modulus were determined by nanoindentation. Based on the experimentally observed morphology and measured mechanical properties, a finite element model of the columnar structure was established in ABAQUS, and the instability responses predicted by solid, shell, and beam element models were comparatively analyzed. The results showed that the as-deposited TiN coating exhibited a dense and uniform surface and a distinct columnar microstructure in cross-section. Linear buckling analysis indicated that the first-order critical buckling loads predicted by different element models were different, among which the solid element model gave a value of 3.43 × 10−5 N, showing the closest agreement with the theoretical result. Furthermore, nonlinear buckling analysis was performed by introducing an initial geometric imperfection of 4 × 10−3 mm based on the first-order buckling mode of the solid element model. The results showed that the columnar structure became unstable at a load of 0.74 × 10−6 N, accompanied by irreversible deformation. These findings demonstrate that linking experimentally observed TiN columnar microstructures with microstructure-informed instability analysis provides a useful perspective for understanding the local instability behavior and potential failure tendency of sputtered coatings and offers theoretical support for the structural design and reliability evaluation of protective coatings for cutting tools.

Inorganics doi: 10.3390/inorganics14050136

Authors: Katherine Ortiz-Paternina Rodrigo Ortega-Toro Joaquín Hernández-Fernández

CO2 adsorption on subnanometric metal clusters is highly sensitive to the computational protocol used to describe the potential energy surface, particularly when several low-lying geometries and spin states are accessible. In this work, CO2 adsorption on Cu4 and Sc4 clusters was investigated using density functional theory (DFT) to evaluate how the choice of functional/basis-set protocol, spin multiplicity, initial geometry, and vibrational stability affects the predicted adsorption behavior. Four representative computational protocols (TPSSh, r2SCAN-3c, PBE-D4/def2-TZVP, and PBE0-SDD) were assessed for isolated clusters and cluster–CO2 complexes. The lowest harmonic vibrational frequency, ωmin, was used as a diagnostic criterion to distinguish true minima from unstable or weakly defined stationary points. Selected cases were also cross-checked using the ORCA and Gaussian quantum-chemistry packages to assess whether comparable computational settings yielded consistent stationary-point character. The results show that Cu4 generally exhibits weak CO2 binding, whereas Sc4 displays stronger but more protocol-dependent adsorption, consistent with its higher structural flexibility and more pronounced Lewis-acid character. Low-frequency and imaginary modes were found in several optimized structures, indicating that adsorption energies should not be interpreted without prior vibrational validation. The comparison also shows that variations in functional/basis-set treatment and spin multiplicity can alter both the optimized geometry and the predicted adsorption strength. Therefore, CO2 adsorption on small metal clusters should be discussed using combined structural, vibrational, and energetic criteria rather than electronic adsorption energies alone. Overall, this study provides a protocol-oriented framework for evaluating the reliability of DFT predictions in CO2 adsorption on Cu4 and Sc4 clusters.

Inorganics doi: 10.3390/inorganics14050135

Authors: Taiwei Gu Jie Yu Fengshuo Xi Xiufeng Li Shaoyuan Li

With the rapid development of the photovoltaic industry, the issue of high-value conversion and utilization of end-of-life photovoltaic modules emerges. This study proposes using them in silicon-air batteries and designs a one-step pretreatment process to obtain two types of anode materials: AB@Si and TC@Si. Additionally, to enhance the electrochemical performance of retired crystalline silicon from PV modules as anodes for silicon-air batteries and improve their mass conversion efficiency, this study introduces Triton X-100 into the KOH electrolyte to inhibit chemical corrosion of the anodes and investigates the mechanism of action of Triton X-100. The results indicate that the surfaces of AB@Si and TC@Si exhibit a pyramidal structure, demonstrating excellent passivation resistance when used in silicon-air batteries, with maximum mass conversion efficiencies of 3.5% and 1.83%, respectively. Under the influence of Triton X-100, the maximum mass conversion efficiencies reach 6.39% and 3.09%, respectively. Polarization curves and mass loss under non-current conditions indicate that Triton X-100 primarily affects the chemical corrosion process of the silicon anode, while its impact on electrochemical corrosion is negligible. Results from contact angle measurements and adsorption energy calculations indicate that Triton X-100 adsorbs onto the silicon surface via benzene ring groups or OH groups, reducing hydrophilicity and delaying the self-corrosion process of silicon, thereby improving the battery′s discharge lifespan and mass conversion efficiency.

Inorganics doi: 10.3390/inorganics14050134

Authors: Faouzia Tayari Silvia Soreto Teixeira Manuel Pedro F. Graca Kais Iben Nassar

The journal retracts the article entitled “A Comprehensive Review of Recent Advances in Perovskite Materials: Electrical, Dielectric, and Magnetic Properties” [...]

Inorganics doi: 10.3390/inorganics14050133

Authors: Maria Gancheva Reni Iordanova Iovka Koseva Georgi Avdeev Petar Ivanov

The pure and xDy3+-doped SrMoO4 series (x = 0.5, 1.0, 1.5 and 2.0 at.%) were synthesized using a direct mechanochemical route. We found that a milling speed of 850 rpm and a milling time of 30 min result in a complete chemical reaction at different concentrations of dopant ions. The phase formation, structural units, and optical properties of the obtained samples were investigated by XRD, IR, UV-Vis and PL analyses. It has been established that Dy2O3 mainly influences the lattice parameters, unit cell volumes, crystallite sizes, and microstrains. The symmetry of MoO4 groups was investigated using IR spectroscopy, and it showed that pure and Dy3+-doped SrMoO4 samples are built up of deformed structural units. The calculated optical band gap of the obtained crystal phases decreases with increasing concentrations of Dy3+ ions. The host SrMoO4 matrix shows broad blue emission centered at 430 nm under an excitation wavelength of 230 nm. All doped samples display a strong yellow emission at 570 nm, belonging to the 4F9/2 → 6H13/2 transition of Dy3+ ions. The highest luminescence intensity was observed when the concentration of the Dy3+ ion was 0.5 at.%. The mechanism of concentration quenching was mainly caused by the electric dipole–dipole interaction. The calculated CIE chromaticity coordinates of the doped samples fall in the yellow range. This study demonstrates that mechanochemical treatment is an appropriate route for the fast preparation of yellow phosphors.

Inorganics doi: 10.3390/inorganics14050132

Authors: Mutaz Salih Soad S. Alzahrani Tarig G. Ibrahim Mohamed R. Elamin Naif Alarifi Ahmed A. Alhadi Babiker Y. Abdulkhair

This work focused on synthesizing MgSiO3 (0%Mo@MgSi), 2.5%MoO3@MgSiO3 (2.5%Mo@MgSi), 5%MoO3@MgSiO3 (5%Mo@MgSi), and 10%MoO3@MgSiO3 (10%Mo@MgSi) by a single-step process utilizing butylated hydroxytoluene (BYHT) as a novel capping agent. The X-ray diffraction analysis of the synthesized nanohybrids indicated amorphous nanohybrids, while the energy-dispersive X-ray spectroscopy results illustrated variations in the MoO3 doping dosages. The 0%Mo@MgSi, 2.5%Mo@MgSi, 5%Mo@MgSi, and 10%Mo@MgSi nanohybrids exhibited average sizes of 17.6, 12.2, 11.7, and 9.9 nm, respectively, and surface areas of 43.53, 40.95, 42.17, and 44.98 m2·g−1, respectively. The examination of 0%Mo@MgSi, 2.5%Mo@MgSi, 5%Mo@MgSi, and 10%Mo@MgSi nanohybrids toward the oxytetracycline (OTC) sorption resulted in qt values of 72.89, 116.89, 98.39, and 78.46 mg·g−1, respectively. The OTC sorption onto the 0%Mo@MgSi, 2.5%Mo@MgSi, 5%Mo@MgSi, and 10%Mo@MgSi aligned with the nonlinear pseudo-second order model, and both the intraparticle and liquid-film diffusion models co-influenced the OTC sorption onto the four nanohybrids. Increasing the temperature decreased OTC sorption on 2.5%Mo@MgSi, indicating exothermic sorption. The Langmuir isotherm model was more suitable than the Freundlich model for describing OTC adsorption on 2.5%Mo@MgSi. The Dubinin–Radushkevich energy (ED ≤ 8.0 kJ·mol−1) and the Gibbs free energy (ΔG° ≤ 20 kJ·mol−1) supported each other’s outcomes about the OTC removal onto 2.5%Mo@MgSi being via physisorption. The ΔG° values increased proportionally with temperature, indicating that OTC sorption becomes more spontaneous as temperature decreases. Moreover, the 2.5%Mo@MgSi exhibited excellent stability in OTC elimination up to the third cycle.

Inorganics doi: 10.3390/inorganics14050131

Authors: Jihao Chen Jingwen Wang

Cyclic pollutants such as dyes, antibiotics, phenols and VOCs in water and atmosphere feature stable structures and are difficult to mineralize, which constitutes the core problem in current environmental governance. Semiconductor photocatalysis provides a green strategy for the advanced treatment of such pollutants. Electrospun black TiO2/Ag-loaded SiO2 nanofiber membranes have become a research hotspot owing to their multi-component synergistic advantages. This paper systematically reviews the preparation processes and structure regulation methods of electrospun SiO2 nanofiber membranes; expounds the loading strategies of black TiO2 and Ag nanoparticles, the interface regulation mechanisms and the synergistic photocatalytic mechanism of the ternary composite system; summarizes the application progress in the degradation of cyclic pollutants in water and atmospheric VOCs; and emphatically analyzes the performance characteristics and key issues in the ring-opening degradation of cyclic pollutants. Studies show that the high specific surface area and porous structure of SiO2 nanofiber membranes offer excellent support for catalytic reactions. In addition, black TiO2 achieves a full-spectrum response through defect engineering; the SPR effect and Schottky barrier of Ag significantly improve carrier separation efficiency; and the synergistic effect of the three components enhances the adsorption–catalytic degradation capacity. Current challenges remain in ring-opening efficiency and stability, requiring multi-method breakthroughs to overcome bottlenecks, clarify mechanisms and promote engineering applications. This paper provides theoretical references for the development of high-performance fiber-based photocatalytic materials and lays a foundation for the practical application of electrospun inorganic nanofiber membranes in the field of environmental catalysis.

Inorganics doi: 10.3390/inorganics14050130

Authors: Łukasz Szeleszczuk Katarzyna Mądra-Gackowska Marcin Gackowski

The structural, mechanical, electronic, and optical properties of cubic double perovskite oxides A2TiSiO6 (A = Ca, Sr, Ba) were systematically investigated using first-principles density functional theory calculations. Structural optimization within the GGA–PBE framework confirms that all compounds crystallize in a stable cubic phase. The negative formation energies indicate thermodynamic stability and potential experimental synthesizability. Ab initio molecular dynamics (AIMD) simulations performed at 300 K further confirm the dynamical stability of all compounds under finite-temperature conditions. The Born–Huang stability criteria performed elastic constant analysis establishes mechanical stability and the derived mechanical moduli indicate the presence of rigid but brittle behavior with moderate amounts of elastic anisotropy. Calculation of the electronic band structure reveals that all the compounds are direct wide-bandgap semiconductors, with the HSE06 bandgaps of Ca2TiSiO6, Sr2TiSiO6 as well as Ba2TiSiO6 being 2.61, 2.50 and 2.37 eV, respectively. The optical property analysis has shown that they are strong in terms of their absorption in the visible–ultraviolet region, with high dielectric constants and good refractive indices, which makes them appropriate in optoelectronics and photovoltaic applications. On the whole, A2TiSiO6 double perovskites are promising for use as wide-bandgap materials in the development of superior optoelectronic devices.

Inorganics doi: 10.3390/inorganics14050129

Authors: Gaizhi Lyu Fanglin Lan Honglian Song Yuanxia Lao Sen Sun

High-entropy oxide (HEO) thin films hold significant potential for applications in spintronics and catalysis; however, their widespread utilization is hindered by weak room-temperature ferromagnetism (RTFM). Herein, we demonstrate a facile vacuum annealing strategy to enhance the RTFM of HEO thin films. (FeNiAlCrMn)O films exhibit a saturation magnetization (MS) of 5.9 emu/cm3 and a Curie temperature (TC) of 350 K after vacuum annealing at 1173 K. Mechanistic investigations reveal that the enhanced RTFM originates from an annealing-induced phase transition from rocksalt-to-spinel. Structurally, annealing facilitates cation diffusion from octahedral to tetrahedral sites, forming a highly crystalline, long-range magnetic lattice of spinel ferrite. Electronically, tetrahedral occupation shortens M–O bonds, drives electron transfer toward metal cations, and enhances orbital hybridization, thereby strengthening magnetic exchange coupling. This study provides a simple and effective strategy for tailoring the RTFM of HEO thin films.

Inorganics doi: 10.3390/inorganics14050128

Authors: Adriana Marizcal-Barba Gerardo Vallejo-Espinosa Yéssica V. Contreras-Pacheco Carlos A. Soto-Robles Karina Nava-Andrade María del Camen Leal-Moya Suresh Ghotekar Mamoun Fellah Claudia M. Gomez Osmín Avilés-García Alejandro Pérez-Larios

The pharmaceutical industry is a major source of pollution in wastewater effluents, characterized by chemical residues that are complex and difficult to degrade. Naproxen, a commonly detected drug in sewage effluents, exceeds safe concentrations for aquifers and is highly persistent, posing significant risks to aquatic life and ecosystems. This drug is known to cause long-term side effects in humans, such as gastrointestinal ulcers and nephrosis, associated with frequent and prolonged use. Additionally, the recent pandemic has led to a marked increase in drug consumption over a short period, exacerbating environmental contamination. Titanium dioxide has been extensively used as a photocatalyst in recent decades, proving effective in reducing these emerging pollutants. In this study, TiO2 doped with cerium was synthesized using the sol–gel method, with cerium concentrations varied at 1, 3, 5, and 10% by weight. The resulting nanocatalysts were characterized through nitrogen physisorption, scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-Vis diffuse reflectance spectroscopy. Photocatalytic activity was assessed using a UV-Vis spectrophotometer to monitor the degradation of the drugs. XRD analysis confirmed the crystallinity and anatase phase of TiO2. UV-Vis diffuse reflectance spectra indicated a decrease in bandgap energy of up to 3.00 eV compared to pure TiO2. The materials demonstrated significant degradation of naproxen (NPX) and acetaminophen (ACTP), both prepared at 30 ppm, over a 6 h reaction period.

Inorganics doi: 10.3390/inorganics14050127

Authors: Zixuan Liu Huafeng Zhou Haiyong He Deyu Wang Zhoupeng Li Zhengfei Chen

In recent years, silicon-based anodes have become a model of commercial success among various high-capacity electrode materials. They also offer a promising substitute for the lithium metal anode (LMA) in lithium–air batteries (LABs), which have the highest specific energy. However, the poor air stability of lithiated silicon-based anodes makes pre-lithiation considerably more difficult and costly in mass production to improve their initial Coulombic efficiency and cyclability, which complicates their material design and electrode manufacturing. To address this issue, intensified efforts have been devoted in recent years, mainly by constructing encapsulation structures, such as core–shell, pomegranate-like or peapod-like architectures. These designs have achieved significantly boosted stability in dry air and, in some cases, even under prolonged exposure to ambient humidity. On the other hand, it was found that silicon-based anodes often provide better cyclic stability than LMAs in LABs and lithium–oxygen batteries (LOBs); however, in most cases, the silicon-based anodes were not optimized for air stability. This review summarizes the relevant works on improving the air stability of silicon-based anodes and LABs/LOBs that used a silicon-based anode, intending to shed light on future development of air-stable silicon-based anodes and bridge the gap between the electrodes’ air-stability and their application in LABs/LOBs.

Inorganics doi: 10.3390/inorganics14050126

Authors: Christina Eleftheria Tzeliou Konstantinos P. Zois Demeter Tzeli

Since the synthesis of ferrocene in 1951, metallocenes have attracted attention, making the accurate prediction of their electronic structure and ionization energy crucial for understanding their photophysical and electrochemical behavior in materials and in biological systems. Here, we combined Density Functional Theory (DFT), Complete Active Space Self-Consistent Field (CASSCF), NEVPT2 (N-Electron Valence State Perturbation Theory) and Coupled Cluster approaches (CCSD, DLPNO-CCSD(T)) to study the electronic structure, ionization energies (IEs) and absorption spectra of metallocene and metallocenium complexes in the gas phase and in THF implicit solvent. DFT IEs agree closely with NEVPT2 and DLPNO-CCSD(T) values and with experiment values (deviations 0.02–0.3 eV). For CASSCF and NEVPT2, the minimal active space of the d electrons at six orbitals is not enough for the accurate prediction of the IEs, while an extended active space incorporating all 3d metal electrons plus four ligand valence electrons into 15 orbitals improves the calculated IE values. In solution, computed oxidation energies (OEs) in THF reproduce experimental values and follow the Fe > Ni > Co ordering. Substitution of metallocene complexes with chromophore units results in similar OEs. Overall, the substitution effects remain modest: the effect of substitution on OE values results in differences up to 0.2 eV. These results clarify the effect of the metal center on IE and OE values and UV–vis absorption behavior.

Inorganics doi: 10.3390/inorganics14050124

Authors: Johana Herrero Carmen Montoro Raquel Gavara Félix Zamora

Covalent organic frameworks (COFs) have emerged as promising materials for the capture and photoluminescent detection of pharmaceutical contaminants in aquatic environments due to their tunable porosity, high surface area, and structural versatility. This review summarizes recent advances in pristine COFs and COF-based hybrid materials for water treatment, focusing on both the adsorption and photoluminescent sensing of pharmaceutical pollutants. The influence of framework design, linkage type, and functionalization on adsorption performance and selectivity is discussed, together with the main interaction mechanisms involved. In addition, recent developments in photoluminescent COFs for sensitive and rapid drug detection are highlighted. Attention is given to dual-function materials capable of simultaneous capture and detection, which represent an emerging strategy for efficient water remediation. Finally, current challenges related to stability, selectivity, and real-world applicability are outlined, providing perspectives for the design of next-generation COF-based systems.

Inorganics doi: 10.3390/inorganics14050125

Authors: Tianyi Liu Wenjie Wang Wenzhuang Liu Hui Xu Jinghua Wu

All-solid-state lithium batteries (ASSLBs) are widely regarded as a promising next-generation energy-storage technology because they offer the potential to simultaneously improve the safety and energy density of conventional lithium battery systems. Among various solid electrolytes, Li-argyrodite sulfide electrolytes (Li6PS5X, X = Cl, Br, I) have attracted considerable attention owing to their high room-temperature ionic conductivity, good mechanical deformability, and favorable cost-effectiveness. However, for the practical deployment of Li-argyrodite sulfide electrolytes in ASSLBs, several critical challenges still need to be addressed, including limited synthesis strategies, insufficient air stability, and poor interfacial compatibility with both cathodes and anodes. This review summarizes recent advances in Li-argyrodite sulfide electrolytes from fundamental understanding to practical applications. The crystal structure characteristics and Li+ conduction mechanisms are first discussed to elucidate the origins of fast ion transport, followed by an overview of major synthesis strategies. Strategies for improving ionic conductivity, air stability, and electrode interfacial compatibility through compositional engineering and interfacial regulation are also highlighted. Finally, the prospects of Li-argyrodite sulfide electrolytes for practical all-solid-state batteries are discussed, together with the remaining challenges and future research directions.

Inorganics doi: 10.3390/inorganics14050123

Authors: Yanhong Ding Yong Cao Zhichao Gao Zijing Zeng Chenyu Xu Teng Fu Jintao Yang Yirong Zhu

This study reports a straightforward and controllable two-step hydrothermal synthesis of novel Ni9S8@NiMoO4/NF nanospherical catalysts supported on nickel foam (NF), accompanied by a systematic evaluation of their performance in the electrochemical hydrogen evolution reaction (HER). Structural characterization revealed a well-defined Ni9S8–NiMoO4 interfacial region, whose synergistic interaction, combined with the distinctive nanospherical morphology, substantially increased the electrochemically active surface area and the density of reactive sites, thereby optimizing HER kinetics. In alkaline media, the Ni9S8@NiMoO4/NF catalyst demonstrated outstanding electrocatalytic performance, delivering an overpotential of only 64.2 mV at a current density of 20 mA cm−2. The catalyst also exhibited a high double-layer capacitance of 22.2 mF cm−2, reflecting a substantial active interfacial area. Long-term durability tests showed negligible performance degradation after 165 h of continuous operation at 10 mA cm−2, underscoring the catalyst’s robust structural stability and durability. X-ray photoelectron spectroscopy confirmed a uniform distribution of Ni, Mo, and S across the NF framework and revealed optimized chemical states, providing material-level evidence for the enhanced performance. Collectively, this work proposes a viable strategy for designing efficient and stable HER catalysts, contributing to the advancement of green hydrogen production and clean energy technologies.

Inorganics doi: 10.3390/inorganics14050122

Authors: Qinmiao Chen Yi Ni Hongcun Yuan

CuIn5Se8 is reported as a remarkable copper-deficient layer that contains ordered vacancy compounds (OVCs) for high-efficiency chalcopyrite-based solar cells; however, the understanding of its carrier characteristics has remained limited. OVCs could naturally form on the surface of chalcopyrite absorber. In this study, the carrier dynamics characteristics of OVCs were investigated by constructing a junction consisting of chalcopyrite absorber and CdS buffer layer. At first, the band structure of CuIn5Se8 was studied to determine the bandgap properties. Then, thermodynamic stability, defect formation energy, defects and carrier concentration, defect transition energy level of CuIn5Se8 and its Cd doping state (caused by CdS) were comparatively studied. The results suggest that Cd doping has different effects on the defect and carrier characteristics of OVCs with various chemical potentials. However, the OVC always remains n-type under the whole thermodynamically stable region, with contribution from the hallow-level InCu donor defect. Finally, the OVC’s carrier dynamics characteristics were assessed using the collected defect and carrier data. It is indicated that the OVC layer may contribute to the formation of a p-n homojunction in solar cells. Under selenium-rich conditions, the OVC layer increases the carrier density on the n-type side of p-n junction nearly 30-fold, which helps reduce the difference in carrier density and minority current density between two sides of the p-n junction. The conversion efficiency of the solar cell with OVC shows a 7.25% improvement when compared to the control. The distinct behavior of OVCs may serve as a valuable reference for the creation or improvement of a related functional film layer or device.

Inorganics doi: 10.3390/inorganics14050121

Authors: Tanya Zhivkova Hristo Hristov Radostina Alexandrova Abedulkadir Abudalleh Lora Dyakova Peter Dorkov Juliana Ivanova

In this study, we present new data about the cytotoxic activity of metal complexes of salinomycin with Co(II), Cu(II) and Zn(II) against human cervical cancer (HeLa) and melanoma (A375, SH-4) cell lines. The effect of the compounds on cell viability and proliferation was evaluated in short-term experiments (up to 72 h) with monolayer cultures using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, neutral red uptake (NR), crystal violet staining (CV) and double staining with acridine orange (AO) and propidium iodide (PI). The cytotoxic effect of the metal complexes of salinomycin was found to be comparable and even superior to that of the commercial antitumor agents cisplatin and oxaliplatin. Long-term experiments revealed the ability of the compounds to completely suppress 3D cell growth when applied at concentrations ≥ 3.1 μM (for HeLa cells) and ≥6.2 µM (for A375 cells). Embryonic Lep-3 cells are highly sensitive to the influence of the complexes investigated, whereas non-tumor HaCaT human keratinocytes exhibit relatively higher resistance to their cytotoxic effect compared to tumor cell lines. The Zn(II) disalinomycinate exerted the highest selectivity index among the tested compounds against melanoma cells, whereas the non-coordinated antibiotic showed pronounced selectivity toward HeLa cells.

Inorganics doi: 10.3390/inorganics14050120

Authors: Mpho Phillip Motloung Mokgaotsa Jonas Mochane

Water pollution caused by harmful organic pollutants discharged from various industries, such as textiles, pharmaceuticals, papermaking, and printing, is resulting in serious health complications and adversely impacting aquatic life. Numerous strategies/methods have been employed to remove these pollutants from water streams. Amongst them, photocatalysts have proven effective in tackling these issues. Zinc oxide (ZnO) and titanium Dioxide (TiO2) photocatalysts are at the forefront due to their exceptional properties, which render them ideal for wastewater treatment. However, their full capacity as photocatalysts is limited by the wide band gap and faster electron-hole recombination rates. Metal decoration on the surface of these semiconductors is one of the fascinating strategies to address these limitations. In this brief review, the synthesis, morphology, and photocatalytic activity of ZnO and TiO2 decorated with metal nanoparticles (NPs) towards the degradation of harmful organic pollutants from various industries are presented. Metal decoration of the surface of ZnO and TiO2 is a viable method to enhance the photocatalytic activity of these semiconductors, particularly under visible light.

Inorganics doi: 10.3390/inorganics14050119

Authors: Yongjie Zhao Weixin Ge Tiebao Wang Pan Gong Wei Yang Lichen Zhao Xin Wang

Controlling the microstructure of electroless nickel coatings is crucial for optimizing the interfacial properties of carbon fibers. However, a systematic understanding of how dispersants can effectively leverage the refining effect of nanoparticles in composite plating systems remains lacking. This paper proposes the use of a composite dispersant, comprising polyethylene glycol (PEG) and sodium methylene bis-naphthalene sulfonate (NNO) at a 1:1 mass ratio, for nano-Al2O3 to achieve microstructure refinement of nickel coatings on carbon fiber surfaces. The results demonstrate that the composite dispersant modifies the surface state and dispersion stability of Al2O3 particles through synergistic adsorption, thereby regulating the nucleation and growth behavior of the Ni-P alloy. At an optimal composite dispersant concentration of 3 g/L, the coating exhibits the most compact structure, with Ni-P particle size refined to approximately 181 nm. The coating consists of two phases: crystalline Ni3P and amorphous Ni-P. The dual adsorption effect of the dispersant—inhibiting Al2O3 agglomeration while improving the surface wettability of carbon fibers—is key to enhancing the refinement efficiency. Conversely, excessive dispersant addition leads to deteriorated coating quality. This study provides experimental evidence for understanding the multiphase interfacial interaction mechanism involving organic additives, nanoparticles, and metal deposition, and offers a novel strategy for controlling the surface functionalization of carbon fibers.

Inorganics doi: 10.3390/inorganics14040118

Authors: Saleh Alyahya Mohamad Arnaout Marc Al Atem Mutaz A. Alanazi Bedir Yousif Alaa A. Zaky

This work proposes the doping of bi-electron transport layers consisting of TiO2/SnO2 with iron to facilitate electron movement and recombination reduction, which results in increases in power conversion efficiency and stability enhancement. Two different PSC structures are used: device 1—FTO/TiO2/SnO2/MAPbI3/Spiro-OMETAD/Ag; device 2, a modified device—FTO/TiO2/SnO2 + Fe/MAPbI3/Spiro-OMETAD/Ag. Characterization analysis revealed an improvement in perovskite crystallinity in the modified device; this leads to reductions in trap state density and the recombination of charges that enhance charge extraction. UV-vis absorbance enhancement in the modified device revealed an enhancement in the perovskite layer morphology and good coverage. As a result, PSCs with a short circuit current of 23.35 mA/cm2, open circuit voltage of 1.07 V, fill factor of 0.73, and high PCE of 18.17% are obtained from device 2, compared to PSCs with only 22.13 mA/cm2, 1.03 V, 0.7, and 16.053% for device 1 without Fe doping, respectively. The results reveal that the device based on Fe doping is more stable than the pristine one under stability tests with regard to aging, thermal, stress and prolonged light.

Inorganics doi: 10.3390/inorganics14040117

Authors: Olga A. Kamanina Vitaliy N. Soromotin Pavel V. Rybochkin Nina M. Ivanova Anton N. Zvonarev Vasilina V. Farofonova

This study demonstrates the feasibility of encapsulating Paracoccus yeei VKM B-3302 cells, which contain palladium nanoparticles, within an organosilicon matrix synthesized using the sol–gel method. The resulting organosilicon material is characterized by a well-developed porous structure and a high specific surface area, ensuring the formation of a catalytic system with accessible active sites. Kinetic studies of the Mizoroki–Heck reaction showed that, although encapsulating the Pd/P. yeei catalyst in an organosilicon matrix slightly decreases its initial reaction rate, it increases the selectivity of the process and reduces the leaching of the active metal during repeated use. These results suggest the potential of encapsulating microorganisms containing metal nanoparticles in organosilicon materials to create stable hybrid catalytic systems.

Inorganics doi: 10.3390/inorganics14040116

Authors: Yufei Li Le Tian Longyao Xu Mingmin Li Huaying Bian Xuetao Wang Shuanghua Wang

This review systematically analyzes the technological progress, structural characteristics, and performance disparities among various diamond grinding wheel bond systems, aiming to establish a unified performance evaluation framework. This framework clarifies material selection criteria and highlights promising research directions. Eight prevalent bond systems are encompassed: resin, metal, ceramic, brazing, electroplating, composite, additive manufacturing, and glass-ceramics. A comparative analysis of these systems is conducted across multiple dimensions. Key evaluation metrics primarily include bond strength, thermal stability, self-sharpening capability, thermal conductivity, and formability. Considerable variations in these indicators are observed across the different bonding agents. Each system presents distinct advantages alongside inherent limitations. Within the constructed multi-metric framework, glass-ceramic bonding agents demonstrate high comprehensive potential in critical aspects such as bond strength and thermal stability, underscoring their research value as a novel high-performance bond system. Current primary challenges focus on the regulation of crystallization kinetics, the design of interfacial reaction layers, and multiscale performance prediction. Future research may advance along several paths. Synergistic design of material composition and microstructure is essential, while in-depth investigation into multiphysics coupling mechanisms remains necessary. Furthermore, data-driven material optimization methods are poised to unlock new possibilities for bond development. These approaches are expected to facilitate the precise design and application of high-performance diamond grinding wheel bonds.

Inorganics doi: 10.3390/inorganics14040115

Authors: Z. Siti Rozaila Siti Fairus Abdul Sani Hans Riesen

We report on X-ray-induced Sm3+ → Sm2+ reduction in SrF2:Sm3+ nanocrystals of ~40 nm size synthesized via a co-precipitation method. Non-irradiated samples show characteristic Sm3+ f-f 4G5/2 → 6H5/2, 6H7/2, 6H9/2, and 6H11/2 emissions, while X-irradiation induces intense low-temperature Sm2+ 5D0 → 7F1 emission and other Sm2+ lines. The evolution of Sm3+ and Sm2+ photoluminescence intensities with X-ray dose (0–300 Gy) follows first-order kinetics, consistent with a trapping–detrapping mechanism. Compared to CaF2:Sm3+, SrF2:Sm3+ exhibits faster Sm3+ reduction due to the higher X-ray absorption cross section of strontium compared to calcium for Cu-Kα (8 keV) radiation, highlighting its potential as a nanoscale X-ray storage phosphor.

Inorganics doi: 10.3390/inorganics14040114

Authors: Nikita S. Aksenin Mikhail S. Bukharov Alexander A. Rodionov Yury I. Kuzin Aidar T. Gubaidullin Daut R. Islamov Valery G. Shtyrlin Nikita Yu. Serov

Copper dithiocarbamate complexes have long been known and are relevant in biology, medicine and material science; however, their low solubility in water can be a limitation. Therefore, the search for modified ligands is an important task. Copper complexes with five phosphorylated dithiocarbamates were investigated in aqueous solutions by several experimental and theoretical methods. Copper(II) bis-complex formation constants were obtained from spectrophotometric titrations. Based on UV-vis and EPR spectroscopy data, the presence of monoligand complexes (in excess copper) and hydroxy-forms (under basic conditions) was revealed. The structures of the obtained forms were optimized using DFT calculations. The instability of complexes under neutral and acidic conditions was established and interpreted by the dimerization upon protonation. This assumption is supported by association constants derived from quantum chemically computed Gibbs free energies for protonated and non-protonated copper(II) bis-dithiocarbamate complexes. Crystal structures of protonated binuclear and non-protonated mononuclear complexes were established using X-ray diffraction. The redox properties of the complexes were studied by cyclic voltammetry; the electrochemical behavior of the complexes was strongly influenced by pH. The scheme of the copper(I)/(II)/(III) species transformations, including chemical and electrochemical stages, is proposed on the base of experimental data and quantum-chemical calculation results.

Inorganics doi: 10.3390/inorganics14040113

Authors: Jiangqin Wang Xuehang Chen Jiangang Zhang Wanliang Yang Tianxiang Li

Accurate quantification of phosphogypsum (PG) filler in epoxy composites is essential for quality control and performance optimization. Conventional separation by muffle furnace calcination suffers from slow epoxy decomposition and risks thermal degradation of CaSO4, leading to inaccurate PG quantification. This study introduces a microwave-assisted separation method that leverages molecular vibration heating to achieve faster heating rates and more uniform temperature distribution, enabling complete epoxy removal while minimizing CaSO4 decomposition. Comprehensive characterization (X-ray diffraction, XRD; Fourier transform infrared spectroscopy, FT-IR; scanning electron microscopy-energy dispersive spectroscopy, SEM-EDS) confirms the structural integrity of the isolated PG filler. Among five quantification methods evaluated, inductively coupled plasma optical emission spectrometry (ICP-OES) based on sulfur content provides the highest accuracy (spike recovery: 91–99.8%, relative standard deviation, RSD ≤ 4.2%), while gravimetry suffices for single-filler systems. This work establishes a reliable analytical framework for PG characterization in epoxy composites, supporting quality control and resource valorization.

Inorganics doi: 10.3390/inorganics14040112

Authors: Jie Zhang Bo Feng Zhiwen Yang Xuan Liu Shilang Guo Jiahao Zhang Zhifen Hong Rong Zhang Tongqiang Xiong Jiang Zhu Wenhua Dai Suoluoyan Yang Sheng Yang

To address the long-standing bottleneck of inherent trade-off between thermoelectric performance and mechanical stability in pure In2O3 thermoelectric materials, this study puts forward a novel optimization route by innovatively adopting Yb2O3 as the dopant, pioneering the dual regulation of defect engineering and electronic structure reconstruction to achieve synchronous thermoelectric–mechanical property synergy, which breaks the limitation of traditional single-property doping modification for oxide thermoelectrics. For electrical transport, Yb3+ induces oxygen vacancy donor defects to boost carrier concentration, and targeted orbital hybridization narrows the band gap and elevates density of states near the Fermi level, synergistically lifting conductivity and offsetting the weakened Seebeck coefficient to optimize power factor with he maximum power factor improved from 1.83 μWm−1K−2 to 5.67 μWm−1K−2. For thermal transport, doping-induced lattice distortion and multi-scale defect system build intensive phonon scattering centers, sharply suppressing lattice thermal conductivity and lowering total thermal conductivity. This synergistic optimization pushes the maximum ZT value to 0.358, a remarkable breakthrough for In2O3-based materials. Meanwhile, Yb2O3 doping reinforces Vickers hardness via lattice distortion strengthening and defect bonding enhancement, eliminating the inherent performance trade-off. This work verifies Yb2O3 doping as a highly efficient strategy, offering solid theoretical basis and practical guidance for developing high-performance, high-stability oxide thermoelectric materials for practical applications.

Inorganics doi: 10.3390/inorganics14040111

Authors: Yan Yan Tong Xu Chenlong Wang Yuhan Fu Bin Zhu

Indoor air pollution, listed by the World Health Organization (WHO) as one of the top 10 environmental risk factors for human health, significantly elevates the risk of respiratory diseases, cardiovascular diseases, and cancers upon long-term exposure. Traditional indoor air purification technologies dominated by physical adsorption and filtration have inherent limitations, including mere pollutant phase transfer, easy saturation, and secondary pollution, while chemical purification centered on pollutant mineralization and degradation is the core development direction for radical elimination of indoor air pollution. Novel nanomaterials, featuring ultra-high specific surface area, precisely tunable active sites and electronic structures, and excellent room-temperature catalytic activity, have become the research focus in this field. This review systematically summarizes the characteristics of typical indoor air pollutants and purification scenario requirements, clarifies the core advantages of chemical purification technologies, details the research progress of novel nanomaterial systems in indoor air chemical purification, and dissects the reaction mechanisms and material optimization strategies of core pathways (photocatalysis, room-temperature thermal catalysis, electrocatalysis, plasma catalysis). We also outline the engineering application status and bottlenecks of these nanomaterials, propose systematic future development directions targeting existing challenges, and aim to provide a reference for fundamental research and industrial application of novel nanomaterials in indoor air purification.

Inorganics doi: 10.3390/inorganics14040110

Authors: Wei Wang Shuangqing Xu Xiao Li Tengfei Cheng Yongtao Li Wanggang Fang Xinghai Ren Liqing He

Hydrogen absorption kinetics in metal hydride beds is constrained by coupled heat and mass transfer, which often leads to a slow refueling response and reduced storage system efficiency. In this work, hybrid molding by mixing silicone gel with various thermally conductive additives was used to prepare TiMn-based metal hydride beds with tailored porosity and thermal conductivity. Three experimental groups were prepared: 5 wt.% silicone gel and 5 wt.% single-walled carbon nanotubes (Group A), 5 wt.% silicone gel only (Group B), and 5 wt.% silicone gel and 5 wt.% silicone sheets (Group C). Hydrogen absorption kinetics at 30 °C and 50 bar were measured experimentally and simulated using a coupled heat-mass transfer model in COMSOL Multiphysics. The physical property results showed that Group A exhibited approximately threefold higher porosity (0.527) compared with the other two groups, while its thermal conductivity (2.476 W·m−1·K−1) was the lowest among them (3.189 W·m−1·K−1 for Group B and 3.246 W·m−1·K−1 for Group C). These property differences led to distinct hydrogen absorption rate-limiting behaviors. Group A dominated in the diffusion-controlled stage (hydrogen uptake between 0.5 and 1.15 wt.%) due to enhanced hydrogen transport through its macroporous network, while Group C exhibited faster kinetics in the later stage (above 1.15 wt.%), where thermal conductivity governed the absorption driving force. Numerical simulations reproduced the experimental kinetic curves and confirmed the transition of rate-limiting mechanisms. This work reveals that the rate-limiting factors of hydrogen absorption in hybrid molding hydride beds vary across different stages, and that independent optimization of porosity and thermal conductivity is required to achieve rapid kinetics across the entire absorption process.

Inorganics doi: 10.3390/inorganics14040109

Authors: Esneyder Puello Polo Elíseo Díaz Varela Carlos A. T. Toloza

The influence of zirconia incorporation and template type on the physicochemical properties of NiMo/Al2O3-ZrO2 catalysts was investigated for the hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DMDBT) and the hydrogenation (HYD) of naphthalene (N). Catalysts were prepared by co-impregnation on supports synthesized via a sol-gel method using starch (A) and activated carbon (C) as structure-directing templates, followed by zirconium incorporation through a grafting procedure. The resulting materials were characterized by SEM–EDX, N2 physisorption, H2-TPR, XPS, HRTEM, and pyridine-FTIR. SEM-EDX confirmed homogeneous metal distributions and compositions close to nominal values (Mo = 20 wt%, Ni = 5 wt%, Zr = 11 wt%) with Ni/(Ni + Mo) = 0.30. N2 adsorption–desorption isotherms correspond to type IV(a) with H3-H4 hysteresis loops, characteristic of mesoporous structures. After metal incorporation, surface areas decreased to 96 m2 g−1 for NiMo/Al2O3 and 81 m2 g−1 for Zr-modified catalysts, while the activated carbon-templated sample preserved a larger mesoporous volume (0.335 cm3 g−1) and higher macroporosity (72%). H2-TPR profiles indicated improved reducibility for Zr-containing catalysts. XPS revealed an increase of MoS2 species from 45% in NiMo/Al2O3 to 75% in NiMo/Al2O3-ZrO2(C), accompanied by a higher degree of sulfidation index (DSI) from 47.1% to 73.9%. HRTEM analysis of Zr-modified catalysts revealed longer MoS2 slabs (11.8–12.1 nm) and higher edge-to-corner ratios (17–17.4) compared with NiMo/Al2O3 (6.2 nm; fe/fc = 8.2). Pyridine-FTIR showed a substantial increase in total acidity from 91 to 421 μmol g−1 upon Zr addition. Catalytically, NiMo/Al2O3-ZrO2(C) exhibited the highest HDS conversion (40%), reaction rate (10.5 × 10−9 mol s−1 g−1), and TOF (4.69 × 10−5 s−1), whereas NiMo/Al2O3-ZrO2(A) reached the highest naphthalene conversion (97.18%), with a reaction rate of 27.4 × 10−7 mol s−1 g−1 and TOF of 12.9 × 10−3 s−1. These results demonstrate that Zr incorporation and the activated carbon template favored hydrodesulfurization, whereas the starch template promoted hydrogenation performance.

Inorganics doi: 10.3390/inorganics14040108

Authors: Jie Dong Xiang Xiong Xin-Yu Tian Man Yu Ning Wang Jie-Zheng Li

p-Nitrophenol (PNP) and bis(4-nitrophenyl) phosphate (BNPP), as typical persistent and toxic organic contaminants, present significant risks to both ecological systems and human health. Accurately quantifying these compounds using luminescent sensors remains a formidable task. In this study, we successfully synthesized a zinc-based metal–organic framework (Zn-MOF) that functions as a luminescent sensing material. The synthesized Zn-MOF demonstrates exceptional dual-response luminescent detection toward PNP and BNPP, with detection limits as low as 3.49 × 10−6 and 8.43 × 10−6 mol/L, respectively. The sensor maintains high selectivity and functionality even in the presence of various potentially interfering substances commonly found in complex environmental samples. Moreover, the material can be fabricated into a visual sensing film, greatly facilitating its application in on-site rapid detection scenarios. Overall, this work introduces a novel luminescent sensor platform that enables fast and reliable monitoring of PNP and BNPP in environmental contexts, demonstrating strong potential for integration into real-time surveillance and early warning systems.

Inorganics doi: 10.3390/inorganics14040107

Authors: Erxi Zhang Jingxiong Liu Yujia Nie Wei Zhou Feng Li Peixin Xu

To optimize the oxygen reduction reaction activity and long-term stability of the PrBaFe2O6-δ (PBF) cathode for protonic ceramic fuel cell (PCFC), this study employed the sol–gel method to dope Sc at the Fe-site of PBF, preparing a novel PrBaFe1.8Sc0.2O6-δ (PBFS) cathode. The effects of different sintering temperatures on the phase composition, microstructure, and electrochemical performance of the PBFS cathode were systematically studied. Results showed that the PBFS cathode sintered at 1000 °C formed a single cubic perovskite structure, exhibiting excellent chemical compatibility with the electrolyte. Sc doping induced Fe in the cathode to exhibit a mixed valence state of Fe2+/Fe3+/Fe4+, thus significantly increasing the oxygen vacancy concentration. The single cell assembled achieved a peak power density of 1.303 W·cm−2 and a polarization resistance as low as 0.035 Ω·cm2 with H2 as the fuel at 700 °C. Moreover, after 100 h of long-term operation at 650 °C, the power density decayed by only 5.23%, thus demonstrating excellent long-term stability. This study offers an efficient cobalt-free cathode candidate for PCFC.

Inorganics doi: 10.3390/inorganics14040106

Authors: Guan-Ting Pan Aleksandar N. Nikoloski

Electrochemical chlorine production is of considerable industrial importance in areas such as water treatment, chemical manufacturing, and disinfection. However, conventional precious metal-based dimensionally stable anodes (DSAs), such as RuO2- and IrO2-based systems, are limited by high cost and resource constraints, motivating the development of low-cost alternative catalysts. In this study, Mn3O4 electrodes with controllable defect characteristics were fabricated by electrochemical deposition under various processing conditions. The effects of defect modulation and surface modification on the structural, electronic, and electrochemical properties of the electrodes were systematically evaluated. X-ray diffraction analysis confirmed that all deposited films retained a stable tetragonal Mn3O4 crystal structure, indicating that the deposition parameters primarily influenced defect states rather than the bulk phase. Mott–Schottky measurements revealed that the Mn3O4 electrodes exhibited p-type semiconducting behavior, with charge carrier densities on the order of 1014 cm−3, suggesting that oxygen vacancy-related defect states may contribute to the observed electronic properties of the electrodes. To further enhance anodic performance, Pt was introduced onto the Mn3O4 surface via sputtering, resulting in significantly improved charge transfer characteristics. Electrochemical measurements demonstrated that the best performing Pt/Mn3O4 electrodes delivered a current density exceeding 100 mA cm−2 at an applied potential of 1.5 V versus Ag/AgCl. More importantly, defect-enriched Pt/Mn3O4 electrodes exhibited markedly enhanced chlorine evolution activity, with the chlorine production rate increasing from approximately 14 µmol cm−2 to 29 µmol cm−2, corresponding to an enhancement of about 2.07-fold. Faradaic efficiency analysis further showed that sample (g) and sample (n) achieved chlorine evolution efficiencies of 59.2% and 74.6%, respectively, indicating a higher tendency toward chlorine evolution for the Pt-modified electrodes under the tested conditions. These findings suggest that the synergistic combination of defect engineering and surface modification effectively modulates the electronic structure of Mn3O4, providing a viable strategy for improving chlorine evolution performance.

Inorganics doi: 10.3390/inorganics14040105

Authors: Ameny El Haj Achref Mannai Hassen Nouri Karim Choubani Mohammed A. Almeshaal Wissem Dimassi Mohamed Ben Rabha

In this work, the impact of hydrogen plasma treatment on the electrical and electronic quality of multicrystalline silicon (mc-Si) was systematically investigated using plasma-enhanced chemical vapor deposition (PE-CVD). Hydrogen radicals generated in the plasma effectively passivate dangling bonds, reducing electrically active defects and enhancing material quality. Optimized PE-CVD conditions were applied to promote efficient hydrogen incorporation and surface modification. Optical characterization, including reflectivity measurements and FT-IR spectroscopy, confirms the formation of Si–H bonds and a significant reduction in surface reflectivity of up to 66% at 600 nm. Electrical and optoelectronic analyses reveal pronounced improvements in carrier lifetime and diffusion length, increased by 200% and 79%, respectively. In addition, dark current–voltage (I–V) measurements show a 32% decrease in series resistance and a 51% increase in shunt resistance, indicating enhanced charge transport and suppressed leakage currents. These macroscopic electrical improvements are supported by light beam-induced current (LBIC) measurements, which demonstrate a 14% increase in grain boundary current, confirming effective hydrogen passivation and reduced recombination. Overall, hydrogen plasma PE-CVD treatment is shown to significantly improve the electronic quality and photovoltaic performance of mc-Si solar cells.

Inorganics doi: 10.3390/inorganics14040104

Authors: Kanami Matsubara Natsumi Yano Hiroshi Sakiyama Makoto Handa Yusuke Kataoka

Two trinuclear cobalt (Co3)-based metal–organic frameworks, [Co3(CHDC)3(py)4] (2; CHDC = trans-1,4-cyclohexanedicarboxylate, py = pyridine) and [Co3(CHDC)3(mpy)2]· 2DMF (3; mpy = 4-methylpyridine, DMF = N,N-dimethylformamide), were successfully prepared via the solvothermal reactions of Co(NO3)2·6H2O, trans-1,4-cyclohexanedicarboxylic acid, and py/mpy in DMF solution. Single crystal X-ray diffraction analyses revealed that the Co3-secondary building units (SBUs) in 2 and 3 adopt Cooctahedral···Cooctahedral···Cooctahedral and Cotetrahedral···Cooctahedral···Cotetrahedral coordination environments, respectively, and are connected by six CHDC linkers to form two-dimensional sheet structures with a triangular lattice. The structural differences of these Co3-SBUs led to clear differences in the magnetic properties and electronic spin states of 2 and 3; temperature-dependent magnetic susceptibility measurements revealed that 2 and 3 exhibited antiferromagnetic and ferromagnetic interactions, respectively, within the Co3-SBUs. These experimental magnetic results are consistent with the density-functional theory calculations of the model structures of Co3-SBUs, which indicate that the most stable spin states are S = 3/2 for 2 and S = 9/2 for 3.

Inorganics doi: 10.3390/inorganics14040103

Authors: Sheng Wang Han Li Huagen Liang Fu Chen

Photo-Fenton technology is considered an effective method for removing organic pollutants from water. In this work, a novel Mn-doped FeWO4 (Mn-FeWO4) photocatalyst was synthesized via a one-step hydrothermal method and applied for the photo-Fenton degradation of tetracycline (TC). The optimal Mn-FeWO4-0.05 achieved 100% removal of TC within 60 min under visible light irradiation with a degradation rate constant of 0.0793 min−1, which is 4.5 times higher than that of pristine FeWO4. Systematic characterization revealed that Mn2+ ions were successfully incorporated into the FeWO4 lattice, inducing lattice expansion and narrowing the bandgap from 2.37 eV to 2.25 eV, while also adjusting the conduction and valence band positions. This modulation significantly enhanced visible light absorption and promoted the separation and migration of photogenerated electron–hole pairs. In addition, the Mn2+/Mn3+ and Fe2+/Fe3+ dual redox cycles ensure the continuous generation of reactive oxygen species. Radical trapping experiments and electron paramagnetic resonance (EPR) spectroscopy demonstrated that superoxide radicals (•O2−) and photogenerated holes (h+) were the dominant reactive species, while singlet oxygen (1O2) and hydroxyl radicals (•OH) played auxiliary roles. Moreover, Mn-FeWO4-0.05 exhibited excellent stability, strong anti-interference ability against common anions, and high degradation efficiency toward various pollutants.

Inorganics doi: 10.3390/inorganics14040102

Authors: Nicholas O. Ongwen Adel Bandar Alruqi

The field of perovskites continues to advance each day, with new materials being discovered in order to eliminate the toxic and less efficient ones. Some of the challenges currently facing the perovskite industry include coming up with materials with higher electrical conductivity and lower thermal conductivity, as well as p-type semiconductors. In an attempt to address these challenges, this study modeled two novel perovskites from potassium hexachloroosmate (VI) (K2OsCl6) by replacing some of the chlorine atoms with those of silver, then characterized their structural, electronic (using both conventional and hybrid functionals), and thermoelectric properties using Quantum Espresso and BoltzTrap2 codes. The calculations were performed within the framework of density functional theory. The results showed that the novel materials exhibited higher density, lower thermal conductivity, lower band gaps, and positive Hall coefficient, unlike the K2OsCl6 sample. These materials can thus be used in areas such as in p–n junctions, thermoelectric devices, and optoelectronic devices. However, since this study was purely computational, the properties need to be verified through an experimental study.

Inorganics doi: 10.3390/inorganics14040101

Authors: Martha Claros Yanio E. Milian Svetlana Ushak Stella Vallejos

Janus nanoparticles (JNPs) synthesis has caught the scientific community’s attention due to their amphiphilic properties and extensive areas of application. In this work, different new copper–silica-based and silica-based JNPs were synthesized using a novel masking methodology and a self-assembly method based on sol–gel procedures, respectively. Moreover, various techniques were used to characterize the developed nanomaterials, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Two types of copper–silica-based Janus nanoparticles were synthesized with a 40 to 70 nm size, while SiO2-based JNPs of around 135 nm were obtained. The duality of different JNPs was confirmed by SEM and by a simple and economical route based on an emulsion stabilization path: analyzing dispersion/aggregation and associated behavior at the immiscible solvent interface. JNPs exhibited an extended residence time over 20 days at an immiscible solvent interface, thereby enhancing the resulting emulsion interface stability. This behavior highlighted their amphiphilic characteristics in comparison to conventional nanoparticles. Consequently, a procedure to determine nanoparticle amphiphilicity could be further standardized.

Inorganics doi: 10.3390/inorganics14040100

Authors: Petar B. Stanić Amina I. Nurović Tanja V. Soldatović Darko P. Ašanin Marko V. Rodić Biljana M. Šmit Goran V. Janjić

This study presents a thorough investigation of chemical outcomes during the reaction of cisplatin and 2-thiohydantoin ligands in the presence of DMSO. Aided by NMR spectroscopy and quantum chemical calculations, the influence of DMSO substitution on the reaction factors is specified, and key intermediates and products in the reaction mechanism are identified and characterized. Coordination modes, reaction orders, and important thermodynamic parameters, such as Gibbs free energies, stabilization energies, and reaction rate constants, are determined. Molecular docking was utilized to propose the binding modes of the final products to DNA and predict their anticancer properties. The results of this study represent a unique kinetic and mechanistic outlook into the influence of DMSO on platinum(II) coordination, as ligand substitution with DMSO was previously found to alter the coordination environment in a biologically relevant manner.

Inorganics doi: 10.3390/inorganics14040099

Authors: Zhao Shao Fengjiao Cheng

Two-dimensional materials have broad application prospects in the field of optoelectronic devices. As a next-generation power electronic device, AlN materials have obvious advantages in power processing, and their monolayer structure has excellent optoelectronic properties, which is of great significance for the study of 2D AlN monolayers. Properties such as electronic and optical properties of metal-adsorbed AlN (M-AlN) systems have been systematically investigated using density functional theory from first principles. The results of the energy bands of the M-AlN system indicate that the adsorption of Al, Li, Ag, Au, Bi, Cr, Mn, Na, Pb, Sn, Ti, and K metals makes the monolayer AlN magnetic, the incorporation of two metals, Al and Li, is the transition of the monolayer AlN from a semiconductor to a semi-metal, and the introduction of K metal makes the monolayer AlN transition from a semiconductor to a metal. The work function of the M-AlN system shows that the introduction of the metal reduces the work function of the monolayer AlN, especially for K-AlN, which is reduced by 56.12% compared to the monolayer AlN. In addition, the results of the optical absorption spectra of the M-AlN system revealed that the introduction of the metals made the monolayer AlN exhibit high absorption peaks in the visible and near-infrared regions; in particular, the intensity of the absorption peaks of the Ti-AlN system at 557.8 nm reached 7.4 × 104 cm−1 and the intensity of the absorption peaks of the K-AlN system at 1109.3 nm reached 1.01 × 105 cm−1. This indicates that the introduction of Ti and K metal atoms enhances the absorption properties of monolayer AlN in the visible and near-infrared regions. Finally, the time-domain finite difference using spherical metal nanoparticles is used to excite the localized surface plasmon resonance, and the results show a small area of strong electric field around the electric field hotspot of Cr and Li particles, and a good concentration of the electric field strength in the x and y directions. In summary, the system of metal atoms adsorbed on AlN will be favorable for the design of spintronics, field-emitting devices and solar photovoltaic devices.

Inorganics doi: 10.3390/inorganics14040098

Authors: Salah H. Elhory Tarig G. Ibrahim Mohamed R. Elamin Faisal K. Algethami Mohamed S. Eltoum Babiker Y. Abdulkhair Mutaz Salih

In the original publication [...]

Inorganics doi: 10.3390/inorganics14040097

Authors: Daniil N. Yarullin Olga I. Logacheva Viktor V. Aleksandriiskii Maksim N. Zavalishin George A. Gamov

The growing demand for gold in various high-technology applications necessitates the development of efficient and selective methods for its recovery and analysis, which can be achieved using such macrocyclic ligands as crown esters and their aza-substituted derivatives. The present paper reports on the equilibrium constants for the formation of gold(III) complexes with 18-crown-6, 1-aza-18-crown-6, 1,10-diaza-18-crown-6, and the cryptand 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane (Kryptofix 222) in aqueous solution at T = 298.2 K, p = 0.1 MPa, I → 0. The equilibrium constants (log β) for the substitution of chloride ions by macrocycles were determined to be 4.52 ± 0.04, 9.15 ± 0.03, 9.08 ± 0.07, and 11.51 ± 0.08, respectively. Equilibrium constants for protonated and polyligand species are also provided. The complexation mechanism was elucidated using a combination of spectroscopic techniques. UV-Vis and IR spectroscopy confirm the substitution of chloride ligands by the nitrogen donor atoms of the aza-macrocycles within the tetrachloroaurate(III) ion. Furthermore, 1H NMR analysis reveals that the diaza-substituted ligands can form both inclusion complexes, where the gold cation is encapsulated within the macrocyclic cavity, and exclusion complexes. These findings provide a quantitative foundation for the design of novel macrocycle-based extractants and sensors for gold(III).

Inorganics doi: 10.3390/inorganics14040096

Authors: Sinuhe U. Costilla-Aguilar M. J. Escudero-Berzal J. F. López-Perales Edén A. Rodríguez Daniel Arturo Acuña Leal A. Torres-Castro R. F. Cienfuegos-Pelaes

Nd2NiO4+δ was investigated as a Ruddlesden–Popper (RP) cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs), with particular emphasis on its electrochemical performance and oxygen reduction reaction mechanism. The material was synthesized via a polymeric sol–gel route derived from Pechini’s method and evaluated in symmetric cells using Ce0.9Gd0.1O2−δ (GDC) as the electrolyte. X-ray diffraction confirmed the formation of a single RP phase and good chemical compatibility with GDC after thermal treatments at 800 °C. Cathode layers with thicknesses of 8–12 µm were deposited by dip-coating. Electrical conductivity measurements revealed a thermally activated semiconducting behavior governed by Ni2+/Ni3+ small-polaron hopping, with an activation energy of ~1.08 eV. Electrochemical impedance spectroscopy showed a strong temperature dependence of the area-specific resistance, decreasing from 9.18 Ω·cm2 at 600 °C to 0.39 Ω·cm2 at 800 °C. Distribution of relaxation times (DRT) analysis enabled the identification of the dominant electrochemical processes, indicating that oxygen surface exchange reactions are more favorable than charge transfer at the cathode–electrolyte interface, which remains the main limiting step. These results demonstrate that Nd2NiO4+δ is a promising cathode for IT-SOFC operation, while further optimization of the electrode–electrolyte interface is required to enhance its oxygen reduction kinetics.

Inorganics doi: 10.3390/inorganics14040095

Authors: Wen Jiang Leyuan Wang Xiangguang Li Caixian Yan Qiaowen Chang

To develop high-performance iridium phosphorescent complexes, we designed and synthesized a series of iridium phosphorescent complexes (G-1, G-2, B-1, B-2, R-1, R-2) using 3-hydroxy-2-methyl-4-pyrone (maltol, short for mal) and 3-hydroxy-2-ethyl-4-pyrone (ethyl maltol, short for emal) as auxiliary ligands, in combination with 2-phenylpyridine (ppy), 2-(2,4-difluorophenyl)pyridine (dfppy), and 1-phenylisoquinoline (piq) as cyclometalating ligands. We systematically investigated their crystal structures, photophysical behavior, electrochemical properties, and electroluminescent performance. The results revealed that the combination of a pyranone auxiliary ligand with the highly conjugated piq ligand leads to the formation of R-1 and R-2, which possess high molecular symmetry and display favorable photophysical performance. These complexes exhibit solution-phase phosphorescence quantum yields of 64% and 55%, and electroluminescent devices incorporating them reach a maximum external quantum efficiency of 13.4%, with brightness exceeding 13,000 cd/m2 and minimal efficiency roll-off. In contrast, complexes incorporating pyridine-based cyclometalating ligands (ppy, dfppy)—G-1, G-2, B-1, and B-2—display weak emission in solution but show enhanced solid-state emission through π–π stacking, with a maximum quantum yield of 25.8%. Density functional theory calculations and electrochemical analysis indicate that the presence of both the pyranone auxiliary ligand and the piq ligand results in optimized frontier orbital energy alignment, enhanced metal-to-ligand charge transfer, and reduced non-radiative transitions, thereby improving emission efficiency. This study provides a theoretical framework and molecular design strategy for the application of pyranone auxiliary ligands in high-performance iridium phosphorescent materials.

Inorganics doi: 10.3390/inorganics14040094

Authors: Edith Luévano-Hipólito Tomas Osvaldo Espinosa-Nieves Lucio Guillermo López-Yepez Edén Amaral Rodríguez-Castellanos Francisco Javier Vázquez-Rodríguez

The development of cementitious materials with multifunctional performance is increasingly important to address environmental demands and durability requirements in modern infrastructure. This study investigates calcium sulfoaluminate (CSA) cement partially substituted with blast furnace slag (BFS), fly ash (FA), and TiO2 nanoparticles, aiming to combine sustainability with photocatalytic self-cleaning functionality. Phase analysis by X-ray diffraction confirmed the formation of characteristic CSA hydration products, including ettringite, ye’elimite, anhydrite, and calcite, indicating that partial substitution did not disrupt the primary hydration mechanisms. Microstructural observations revealed that the incorporation of BFS, FA, and TiO2 induced noticeable morphological changes, with increased porosity and microstructural heterogeneity at higher replacement levels. Mechanical testing showed that moderate BFS contents of 5 to 10 wt% enhanced compressive strength in reference mixtures, while systems containing TiO2 exhibited slightly lower strength values and increased dispersion, particularly at elevated slag contents. The photocatalytic performance, evaluated through Rhodamine B degradation under solar irradiation, demonstrated a marked improvement for TiO2-containing samples, reaching degradation efficiencies of up to 80%, in contrast to negligible activity in unmodified systems. These results confirm that the combined use of industrial by-products and photocatalytic nanoparticles in CSA-based matrices represents a viable strategy for producing sustainable cementitious materials with added environmental functionality, without compromising fundamental structural performance.

Inorganics doi: 10.3390/inorganics14040093

Authors: Boyu Zhang Ming Zhang Siqi Huang Weie Wang Yuguang Lv Fenghua Liu Xi Cao Kuilin Lv

As a novel organic–inorganic hybrid porous crystalline material, metal–organic frameworks (MOFs) are ideal sensitive materials for detecting gases, antibiotics, and ions, owing to their ultra-high specific surface area, tunable pore structures, abundant active sites, and tailorable architectures. This review systematically summarizes the core structural features, preparation methods, and modification strategies of MOFs, elaborates on the adsorption and signal conversion mechanisms in target detection, and highlights typical applications, performance advantages, and practical scenarios of MOF-based sensors, clarifying their structure–activity relationships and performance differences from traditional semiconductor sensors. It further analyzes key challenges, including insufficient stability, poor conductivity, large-scale preparation difficulties, and real-sample interference, as well as industrialization bottlenecks such as batch-to-batch reproducibility, instrument integration, and high costs. Additionally, it supplements cross-field synergistic innovations and industrialization progress, and prospects future directions: function-oriented precise design, multifunctional composite optimization, portable intelligent devices, green large-scale synthesis, and standardization promotion. This review provides a comprehensive reference for advancing MOF-based detection research and applications in environmental monitoring, industrial safety, food safety, and healthcare.

Inorganics doi: 10.3390/inorganics14040092

Authors: Laura G. Ceballos-Mendívil Eric Manzanarez-Salazar Jonathan C. Luque-Ceballos Rody Soto-Rojo Francisco Baldenebro-López Adriana Cruz-Enríquez Jesús Baldenebro-López

Hafnium carbide (HfC) ceramics are of growing interest due to their exceptional mechanical properties and ultra-high melting points, making them ideal for extreme environmental applications. In this study, we present a synthesis route for HfC nanoparticles via carbothermal reduction of an organic–inorganic hybrid precursor derived from hafnium tetrachloride (HfCl4) and pectin, followed by thermal treatment at 1500 °C for 1.5 h under an argon atmosphere. According to TGA/DSC analysis of the hybrid precursor, hafnia phases initially formed during pyrolysis and were subsequently converted into HfC at 1500 °C, with the endothermic carbothermal reduction reaction initiating near 1200 °C. Comprehensive characterization using Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), X-ray diffraction (XRD) with Rietveld refinement, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed the synthesis of hafnium carbide (HfC) exhibiting predominantly cubic morphology. XRD analysis determined a lattice parameter of a = 4.63 Å and an interplanar spacing of d = 2.68 Å. Rietveld refinement revealed a phase composition of 98.08% HfC and 1.92% monoclinic hafnium dioxide (m-HfO2). Debye–Scherrer analysis indicated an average crystallite size of 67.6 nm. SEM and TEM images showed uniformly distributed nanoparticles with an average particle size of approximately 65–70 nm.

Inorganics doi: 10.3390/inorganics14040091

Authors: Anatolii S. Burlov Anastasia A. Shiryaeva Valery G. Vlasenko Yurii V. Koshchienko Alexander A. Zubenko Oleg P. Demidov Bogdan V. Chaltsev Alexandra A. Polyanskaya Alexey N. Gusev Elena V. Braga Wolfgang Linert

Two Zn(II) coordination compounds based on glaucine-derived Schiff bases were synthesized and investigated as potential materials for dye-sensitized solar cells (DSSCs). The structures of all compounds were established by X-ray diffraction analysis and quantum chemical modeling (DFT/TD-DFT). Their photophysical properties (absorption and luminescence spectra in solution and the solid state), electrochemical characteristics, and photovoltaic parameters in DSSC devices were studied. The highest power conversion efficiency (PCE ~5.18%) was demonstrated by the free ligands, which is attributed to their favorable absorption spectrum and optimal alignment of energy levels relative to the conduction band of TiO2 and the redox couple of the electrolyte. The Zn(II) coordination compounds exhibited significantly lower efficiency (~2.1%). Impedance spectroscopy results indicated more efficient charge transfer at the TiO2/dye/electrolyte interface for the organic derivatives.

Inorganics doi: 10.3390/inorganics14040090

Authors: Chong Ma Chen Yao Jing Xu Yibing Xie

The inorganic proton acid-doped polyaniline (H-PANI-X) is synthesized directly on a graphite carbon paper electrode. The polyaniline doped with hydrochloric acid (yielding H-PANI-Cl), sulfuric acid (yielding H-PANI-HSO4), and nitric acid (yielding H-PANI-NO3) is employed to construct both finite molecule and periodic molecule computational models. Theoretical calculation and experimental measurement of a polyaniline/graphite carbon paper electrode are adopted to reveal the doping effect of inorganic acid radical ions (Cl−, HSO4−, NO3−) on electrical and electrochemical properties of H-PANI-X. H-PANI-X shows a lower electronic band gap structure, indicating more feasible electron transfer than PANI. H-PANI-X shows a lower HOMO-LUMO orbital energy gap, indicating lower excitation energy than PANI. H-PANI-X also shows a higher electronic density of states level, indicating higher electrical conductivity than PANI. The charge density difference of H-PANI-X reveals a more delocalized electrostatic potential distribution, indicating an enhanced electrostatic interaction between protonated PANI and charge-balancing anions. Furthermore, H-PANI-HSO4 and H-PANI-NO3 exhibit hydrogen bonding between the protonated PANI and charge-balancing anions, resulting in reduced electronic band gaps and enhanced electronic density of states compared with H-PANI-Cl. H-PANI-NO3 with higher electronic states at the Fermi level and higher anionic electronegativity exhibits higher electrical conductivity than H-PANI-Cl and H-PANI-HSO4. The experimental measurement is conducted to investigate the electrochemical properties of H-PANI-X. The electrochemical impedance spectroscopy measurement indicates H-PANI-NO3 maintains lower charge transfer resistance (0.357 Ω) than H-PANI-HSO4 (3.003 Ω) and H-PANI-Cl (10.571 Ω). The cyclic voltammetry measurement indicates that H-PANI-NO3 has much higher redox current and mean current density responses, accordingly exhibiting superior capacitance (208.0 mF cm−2) performance in comparison with H-PANI-Cl (129.5 mF cm−2) and H-PANI-HSO4 (157.9 mF cm−2). Theoretical calculation and experimental investigation confirm H-PANI-NO3 presents superior electroactivity to H-PANI-Cl and H-PANI-HSO4 for promoting its electrochemical capacitance performance.

Inorganics doi: 10.3390/inorganics14030089

Authors: Angel A. J. Torriero

Electrochemical sensors for oxyanion detection are widely reported across environmental, industrial, and biological contexts, with recent literature often emphasising material innovation and increasingly low detection limits. Despite this activity, translation beyond laboratory demonstrations remains limited, raising questions about how electrochemical signals are interpreted and validated. In this review, recent electrochemical oxyanion sensors are examined from a measurement-centred perspective, focusing on how signals are generated, conditioned, and calibrated across major sensing strategies, including direct faradaic detection, modified-electrode and electrocatalytic systems, accumulation-based approaches, and enzyme- or mediator-assisted architectures. Rather than cataloguing sensor materials or device configurations, the analysis examines the assumptions underlying commonly reported performance metrics. Across sensing strategies, signal behaviour is frequently governed by interfacial chemistry, surface history, and experimental constraints rather than by invariant properties of the target oxyanion. Consequently, sensitivity, selectivity, and detection limits often reflect context-dependent behaviour within narrowly defined laboratory regimes. By synthesising these patterns, the review identifies recurring interpretive limitations in how electrochemical responses are linked to analyte determination. The resulting framework clarifies the analytical basis of the existing literature and highlights design-relevant constraints and validation practices that must be addressed for electrochemical oxyanion sensors to progress from feasibility demonstrations to robust analytical tools.

Inorganics doi: 10.3390/inorganics14030088

Authors: Naifeng Chen Yi Li Chenxia Gao Chao Xue Shuang Liu Jinghang Li Xi Cao Kuilin Lv Yuguang Lv

This study systematically investigated the characterization of 2Fe-CDs/12Mn-CeO2 composites and the colorimetric sensing properties of H2O2, glucose (Glu), and glutathione (GSH). The morphology, structure, and optical properties of the 2Fe-CDs/12Mn-CeO2 composite were analyzed in detail by XRD, FT-IR, SEM, TEM, XPS, and Raman spectroscopy, and its formation was supported by multiple complementary characterization techniques. The catalytic efficiency (kcat/Km) of the nanozyme is 152-fold higher than natural HRP under optimal conditions and remains 59-fold higher even after temperature normalization to 25 °C. In the colorimetric sensing experiments, the detection limits of Fe-CDs/Mn-CeO2 were 0.21 μM, 2.7 μM, and 0.63 μM for H2O2, Glu, and GSH, respectively. Rapid and accurate determination of the concentrations of these biomolecules can be achieved by observing the color changes after Fe-CDs/Mn-CeO2 reaction with the objects to be measured. The experimental results show that Fe-CDs/Mn-CeO2 have high sensitivity and selectivity for H2O2, Glu, and GSH, which provides a solid theoretical and experimental basis for the application of Fe-CDs/Mn-CeO2 in the field of biosensing and medical diagnosis.

Inorganics doi: 10.3390/inorganics14030087

Authors: Yuxin Wang Xiaoxue Tang Siqi Huang Weie Wang Xi Cao Yuguang Lv Xiaoyi Chen

With the deep integration of pharmacy and materials science, functional materials are increasingly applied in drug development, environmental remediation of pharmaceutical pollutants, and clinical diagnosis and treatment. This article focuses on multiple application scenarios of functional materials, including drug degradation, drug adsorption, drug analysis and detection, electrochemical detection, and bioimaging. It systematically reviews the structural characteristics, modification strategies, and latest research progress of typical functional materials such as metal–organic framework materials, nanocomposites and bio-based materials in various application fields. The article also analyzes key challenges faced by functional materials in multi-scenario applications, such as biocompatibility, stability, and large-scale preparation. In light of the trends in precision medicine, it outlines future directions for the application of functional materials in the field of pharmacy, aiming to provide references for the design and development of multifunctional materials and innovative applications in pharmaceuticals.

Inorganics doi: 10.3390/inorganics14030086

Authors: Zixiang Wang Binhao Li Jing Wang Kemeng Nong Shuhui Liu

To address the capacity decay of NCM811 caused by microcracks and cation disorder during cycling, La, Al, and F tri-doped micron-sized single-crystal NCM811 material with a LiNbO3 coating was synthesized via a facile co-solvent method. Using a mixed glucose–urea thermal solution as the reaction medium, metal salts were incorporated, followed by step-wise sintering, ball-milling, heat treatment, and wet-chemical coating. This approach enables atomic-level precursor mixing and ensures homogeneous element distribution. La3+ enlarges the lithium layer spacing to enhance ion diffusion and Al3+ suppresses Ni3+ reduction to Ni2+, mitigating cation mixing and improving conductivity, while F− stabilizes the crystal structure via its strong electronegativity. The LiNbO3 coating protects the interface from electrolyte attack, and the single-crystal morphology effectively suppresses microcracking. Compared to unmodified single-crystal NCM811 prepared identically, the modified material exhibits reduced cation disorder, improved crystallinity, and superior thermal stability. Electrochemical tests in half-cells with 1 M LiPF6/(EC/EMC/DMC) electrolyte (2.8–4.3 V) show an initial discharge capacity of 208.32 mAh/g at 0.1 C and 194.05 mAh/g at 1 C. After 200 cycles at 1 C, the capacity retention remains at 92.21%, exceeding the market average. Rate performance is also notably enhanced, with the 5 C discharge capacity increasing from 141.12 mAh/g (unmodified) to 166.81 mAh/g, demonstrating improved kinetics and structural stability.

Inorganics doi: 10.3390/inorganics14030085

Authors: Giovanna Claudino de Lima João Honorato de Araujo-Neto Marcelo Cecconi Portes Ana Paula Araujo de Oliveira Ana Maria da Costa Ferreira

Carnosine (or β-alanyl-L-histidine) is an endogenous compound playing very important roles in human organisms as antiglycation and antioxidant agents, and, in addition, helping to mitigate illnesses such as cancer and neurodegenerative diseases. Aiming to explore the chelating ability of carnosine, based on its coordinating possibilities, we started to investigate the metal complexes of essential copper(II), zinc(II), and iron(II) ions coordinated to this dipeptide. Different compounds were isolated in the solid state by adding stoichiometric amounts of metal salts to carnosine at controlled pH or under a controlled atmosphere, with the formation of mono-, bi- and polynuclear species. These complexes were subsequently characterized mainly by spectroscopic techniques (UV–Vis, IR, EPR), in addition to elemental analysis. A binuclear species was isolated with copper(II) and had its structure determined by X-ray diffraction, improving previously reported data in the literature. Two insoluble correlated trinuclear species were isolated with zinc(II) ions, using perchlorate or chloride as counter-ions. In the case of iron, a mononuclear species was verified with Fe(II) ions, obtained under an inert atmosphere. Further, the antioxidant properties of free carnosine and the copper–carnosine complex were verified by their scavenging activity toward the ABTS•+ radical, using Trolox as a reference, showing significant activity. The carnosine–metal complexes were also tested as potential antineoplastic agents, in comparison to the free ligand, after 24 h of incubation at 37 °C, using malignant HeLa, SKMEL 28 and SKMEL 147, and non-tumor fibroblast cells. Results indicated neglected or poor anti-proliferative properties of these metal complexes, when compared to other similar compounds described in the literature.

Inorganics doi: 10.3390/inorganics14030084

Authors: Mortaga M. Abou-Krisha Abd El-Motaleb M. Ramadan Heba A. Sahyon Ahmed M. Fathy

Cisplatin’s chemotherapy is hindered by drug resistance and toxicity, making copper complexes a potential alternative. A novel copper(II) complex, [CuLBr], was synthesized from a tetradentate vicinal dioxime ligand (H2L) and characterized. [CuLBr] features a distorted square pyramidal geometry with a CuN4Br chromophore. DFT calculations showed a narrowed HOMO-LUMO gap and increased electrophilicity, enhancing its chemical reactivity. [CuLBr] exhibited potent biomimetic catalytic activity, functioning as an efficient superoxide dismutase mimic and catalase mimic. Biophysical studies (UV-Vis, fluorescence, and viscosity) demonstrated a strong, spontaneous affinity of [CuLBr] for calf thymus DNA and Human Serum Albumin, suggesting groove-binding and static quenching mechanisms. In vitro assays revealed superior anticancer activity against HepG-2, HCT-116, and MDA-MB-231 cell lines, with greater selectivity than the free ligand and doxorubicin. Molecular docking studies reveal a high binding affinity of [CuLBr] with key proteins, including ferredoxin-1 and VEGF. This may suggest potential dual mechanisms of action, involving the induction of cuproptosis and the inhibition of tumor angiogenesis. These findings position [CuLBr] as an effective multi-metal-based anticancer agent with advantageous selectivity.

Inorganics doi: 10.3390/inorganics14030083

Authors: Georgia R. F. Orton Martin Pižl Sara Belazregue Andrew J. Lake Mark R. J. Elsegood Jeremy K. Cockcroft Martin B. Smith František Hartl Graeme Hogarth

While many [FeFe]-hydrogenase biomimetics are effective proton-reduction catalysts, few are active for H2 oxidation, and examples containing both a pendant amine group, able to act as a proton relay, and a second redox center, both essential features of the enzymes, are rare. Here we report the preparation and oxidation chemistry of two ferrocene-functionalized amino-diphosphines (PCNCP), (CH2PR2)2NCH2Fc (R = Ph (1), Cy (2)), and their ethylenedithiolate (edt) diiron complexes, [Fe2(CO)4(μ-edt){κ2-(R2PCH2)2NCH2Fc}] (R = Ph (3), Cy (4)). Their crystallographic characterization shows that PCNCP occupies an apical–basal position. CV responses are slightly R-dependent, showing for 3 and 4 in three separate oxidative processes assigned to successive one-electron oxidation of the diiron core (quasireversible), appended Fc (reversible), and the amine–diiron moiety (irreversible), as confirmed by IR and UV–Vis spectroelectrochemical studies supported by Density Functional Theory (DFT) and Time-dependent Density Functional Theory (TDDFT) calculations. The first oxidation results in a structural rearrangement of the Fe(PNP)(CO) unit and the formation of a semi-bridging carbonyl. Slow protonation of 3 with HBF4∙Et2O affords the corresponding N-protonated cation in acetone, whilst μ-hydride products dominate for both 3 and 4 in CD2Cl2. A preliminary H2 oxidation study was carried out with 3, and while there was some evidence of activity, it was much lower than reported for alkyl-functionalized PCNPC diiron derivatives.

Inorganics doi: 10.3390/inorganics14030082

Authors: Jingfei Luan Yu Cao Jian Wang Liang Hao Anan Liu Hengchang Zeng

A novel catalyst, Tm2FeSbO7, was synthesized by employing the solid-phase high-temperature sintering method, and, for the first time, it was utilized to create a Z-type heterojunction with BiYO3. A direct Z-scheme Tm2FeSbO7/BiYO3 heterojunction photocatalyst (TBHP) was successfully produced by employing the ball-milling technique. X-ray diffraction analysis results indicated that Tm2FeSbO7 crystallized in a cubic pyrochlorestructure which owned the Fd-3m space group, with a unit cell parameter of 10.1769 Å, whereas BiYO3 displayed a fluorite structure in the Fm-3m space group, with a unit cell parameter of 5.4222 Å. The Mossbauer spectrum of Tm2FeSbO7 showed that Fe3+ ions might locate at octahedral sites. The measured bandgap widths for the TBHP, Tm2FeSbO7, and BiYO3 were 2.14 eV, 2.21 eV, and 2.30 eV, respectively. Multiple experimental results demonstrated that the TBHP exhibited a higher valence band ionization potential, a narrower band gap width, and a higher removal efficiency of the sulfamethoxazole (SMX) compared with the Dy2TmSbO7/BiHoO3 heterojunction photocatalyst. Under visible-light irradiation (VISLI) of 115 min, the TBHP showcased exceptional photocatalytic elimination performance; therefore, the elimination rate of the SMX and the total organic carbon (TOC) mineralization rate reached 99.51% and 98.10%, respectively. In contrast to single-component Tm2FeSbO7, BiYO3, or conventional nitrogen-doped titanium dioxide (N-TiO2) catalyst, the TBHP exhibited removal efficiency enhancement for degrading the SMX by 1.17 times, 1.31 times, or 4.06 times. Simultaneously, the matching mineralization rate for removing the TOC density by employing the TBHP was 1.20 times, 1.34 times, or 4.73 times higher than that by employing Tm2FeSbO7, BiYO3, or conventional N-TiO2. Above experimental results indicated that the mineralization efficiency for removing TOC density by employing the TBHP was higher than that by employing Tm2FeSbO7, BiYO3, or N-TiO2. Radicals trapping experiments and the electron paramagnetic resonance spectroscopy results revealed that hydroxyl radicals, superoxide anions, and photoinduced holes were the primary active species during the catalytic elimination course of the SMX by employing the TBHP under VISLI. The results demonstrated that the direct Z-scheme TBHP, which was developed in this study, exhibited the maximal removal efficiency for degrading the SMX in contrast to Tm2FeSbO7, BiYO3, or N-TiO2. Additionally, the possible elimination routes and elimination mechanisms of the SMX were proposed. Therefore, an important scientific foundation for developing high-performance heterojunction catalysts was established.

Inorganics doi: 10.3390/inorganics14030081

Authors: Yi Meng Na Liu Mingyang Hao Peng Du Xue-Zhi Song Xia Li Kaitao Zhang Gangqiang Zhang Yu Pan

Anilido-oxazoline iron(II) chloride complexes were synthesized and evaluated for their catalytic performance in the ring-opening polymerization (ROP) of cyclic esters. Complexes 1–5 were obtained via transmetalation of FeCl2(THF)1.5 and pyridine derivatives with in situ generated anilido-oxazoline lithium. They exhibited excellent controllability and high initiating efficiency in the ROP of ε-caprolactone (CL). In the presence of benzyl alcohol as the initiator, these iron complexes efficiently catalyzed the ROP of CL, reaching a TOF of 3.2 × 103 h−1. High molecular weight polycaprolactone was obtained with a number-average molecular weight of 161.38 kg/mol. The chain initiation and propagation processes were investigated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and kinetic analyses. Kinetic studies confirmed a pseudo-first-order dependence of the polymerization rate on catalyst concentration. Furthermore, the iron(II) complexes were also found to be efficient catalysts for the ROP of δ-valerolactone.

Inorganics doi: 10.3390/inorganics14030080

Authors: Giulia De Felice Devi Rejendran Gaetano Anello Negar Amani Tehrani Fausto Gallucci

Methane (CH4) is the second-largest contributor to climate change after carbon dioxide (CO2) and has a global warming potential about 72 times greater than CO2 over a 20-year timescale. A possible solution to mitigate CH4 emissions from diluted sources is direct removal of CH4 through tailored sorbents. In this work, ion-exchanged zeolites have been investigated, owing to their low cost, excellent chemical stability, and ease of production. The impact of barium, lithium, and nickel exchange was investigated, along with one, three, and five ion-exchange sequences. XRD analysis confirmed that the structure remained intact after ion exchange. However, nitrogen physisorption revealed that nickel- and barium-exchanged zeolites had reduced pore volume and surface area compared to the parent zeolite, possibly due to mesopore formation from lattice strain relaxation. ICP-OES and SEM-EDX confirmed the successful incorporation of metals into the zeolite. Finally, breakthrough experiments were carried out to assess the saturation capacity of the synthesized sample. The results demonstrated that the lithium-exchanged samples provided the highest saturation capacity, namely 1.58 ± 0.05 mmol g−1 for the Li-13X-3 and 1.76 ± 0.07 mmol g−1 for the Li-SAPO34-5 over 10 adsorption cycles. Furthermore, the stability of the Li-SAPO34-5 was confirmed over 100 adsorption cycles.

Inorganics doi: 10.3390/inorganics14030079

Authors: Svetlana V. Sidorova Alexey D. Kouptsov Anastasia A. Felde Alexandre N. Zakharov

Electrodeposition of copper on the surface of the high-carbon steel (HCS) cathode was carried out in situ during the electrolysis of an aqueous KOH solution with a copper anode. A mechanism was proposed for the transfer of the copper from the anode to the cathode, followed by the formation of a copper film on the HCS. The surface roughness of the substrate and the copper coating was studied using AFM and profilographic data. There is a discrepancy between the roughness values of the substrate and coating obtained using different techniques. The surface morphology of the substrate was found to affect the copper film quality. The roughness of the copper coating calculated using AFM data replicated the roughness of the substrate surface. It was found that, despite some difference in the roughness calculated by profilographic and AFM data, the overall roughness trend remains unchanged.

Inorganics doi: 10.3390/inorganics14030078

Authors: Kenian L. Arévalo Blanco Wilder S. Campo Baca Esneyder Puello Polo

In the original publication [...]

Inorganics doi: 10.3390/inorganics14030076

Authors: Cristina Florentina Ciobota Florentina-Gabriela Ioniță Năstase-Dan Ciobota Dumitru-Valentin Drăguț Miruna-Adriana Ioța Ioan-Albert Tudor Ștefania Caramarin Bogdan Florea Dragos-Florin Marcu

The study investigates the structural and thermal properties of zirconia ceramics doped with Sm2O3. The powders were prepared via a mild hydrothermal synthesis route at a temperature of 200 °C, for 2 h with a pressure of 60–100 atm, starting from ZrO2-Sm2O3 compositions. Structural and physicochemical characterization was performed using XRD, SEM-EDAX, BET and FT-IR analyses after synthesis and subsequent heat treatments up to 1500 °C. The results indicate good thermal stability of the materials, while a single cubic phase is achieved after calcination at 1500 °C. The ceramics show low thermal conductivity (0.41 W·m−1·K−1), reduced heat capacity (0.26 J·g−1·K−1), and low thermal diffusivity (0.34 mm2·s−1), with all measured parameters lower than those commonly reported for conventional rare-earth-stabilized zirconia.

Inorganics doi: 10.3390/inorganics14030077

Authors: Xiwei Zhang Junshuai Li Jiale Sang Jiabao Luo Jiayi Shi Huijuan Geng Zhenjie Tang

g-C3N4 has emerged as a promising metal-free semiconductor for optoelectronic applications due to its suitable bandgap, excellent stability, and low cost. However, enhancing its photoresponse efficiency in practical devices remains a challenge. In this work, a high-performance self-powered photodetector was developed using a g-C3N4/textured Si n-n heterojunction fabricated via a simple solution process. The device exhibits excellent diode characteristics with a rectification ratio of ~4.9 × 102 and an ideality factor of 1.41. It achieves broadband detection from 405 to 980 nm, a high responsivity of 3.2 A/W, a specific detectivity of 1.9 × 1014 Jones, and fast response speeds of 44/36 ms at 650 nm under zero bias. Significantly, the textured Si-based device shows approximately tenfold higher performance than its planar Si counterpart, owing to enhanced light absorption from the textured surface. The combination of excellent photoresponse and simple fabrication makes the g-C3N4/textured Si n-n heterojunction a promising candidate for low-cost, high-performance optoelectronic applications.

Inorganics doi: 10.3390/inorganics14030075

Authors: Dušan Dimić

Currently, the development of medicinal chemistry depends on naturally occurring scaffolds, as nearly 50% of FDA-approved compounds are related to compounds already present in nature [...]

Inorganics doi: 10.3390/inorganics14030074

Authors: Alexander Selverian Svilen Bobev

For the first time, the ternary Zintl phases RbCaBi and CsCaBi have been synthesized and structurally characterized via single-crystal X-ray diffraction methods. These two compounds, alongside KCaBi, are confirmed to crystallize in a tetragonal crystal system with the space group P4/nmm (no. 129) with two formula units per cell. The lattice constants increase monotonically from a = 5.3812(10) Å and c = 8.410(3) Å for KCaBi, to a = 5.4139(7) Å and c = 8.6180(17) Å for RbCaBi, and to a = 5.4709(11) Å and c = 8.914(3) Å for CsCaBi. The crystal structure can be visualized as an array of square prisms formed of Bi atoms, which are centered by alkali metal atoms, while the Ca atoms fill tetrahedra formed of Bi atoms. There are no direct Bi–Bi interactions in the crystal structure; therefore, with full cation ordering present, the chemical bonding in the ACaBi compounds can be rationalized within the fully ionic approximation as A+Ca2+Bi3− (A = K, Rb, Cs). This suggests the opening of an (narrow) energy gap between the valence and conduction bands, i.e., semiconducting behavior.

Inorganics doi: 10.3390/inorganics14030073

Authors: Baseerat Bibi Zahra Karimi Syed Hatim Shah Fan Shen Najm Us Sama Linlin Guan Jingjing Zhang Jiale Lin Zhu Liu

Two-dimensional (2D) Ruddlesden–Popper (RP) tin halide perovskites have attracted considerable attention as lead-free photovoltaic absorbers; however, the impact of organic A-site cations on their structure and pressure-dependent optoelectronic behavior remains underexplored. In this study, density functional theory (DFT) is used to investigate the structural, electronic, and optical properties of A2SnI4 (A = GUA+, DMA+, MA+) under ambient conditions and under hydrostatic pressure. All three compounds adopt layered frameworks in which the organic cations occupy the interlayer region, while SnI6 octahedra form the inorganic slabs. Band-gap calculations are performed using HSE06 for ambient pressure, known for its accuracy in electronic structure predictions, and PBE for pressure simulations, due to its computational efficiency in large-scale systems. At ambient pressure, Hybrid-functional (HSE06) calculations indicate that all three materials are direct-gap semiconductors, with band gaps of 2.25 eV for MA2SnI4, 2.98 eV for DMA2SnI4, and 2.85 eV for GUA2SnI4. Under hydrostatic compression, DMA2SnI4 shows comparatively modest band-gap variation and saturates near 1.7 eV. In contrast, GUA2SnI4 and MA2SnI4 exhibit pronounced band-gap narrowing, including a pressure-induced direct-to-indirect transition near 2 GPa, with band gaps decreasing to 0.59 eV (GUA2SnI4) and 0.34 eV (MA2SnI4) at elevated pressures. Overall, these findings highlight that A-site chemistry, combined with hydrostatic pressure, enables tuning the electronic and optical responses in tin-based 2D RP perovskites, demonstrating their promise as tunable, lead-free photovoltaic absorbers.

Inorganics doi: 10.3390/inorganics14030072

Authors: Ran Li Haiyang Pan Mingze Zhang Yanling Lv

Sodium-ion batteries (SIBs) are regarded as an important complementary technology to lithium-ion batteries due to their abundant resources and low cost, demonstrating broad application prospects, especially in large-scale energy storage. As a core component of SIBs, the cathode material directly determines key performance indicators such as energy density, cycling stability, and rate capability. Currently, the main cathode material systems under extensive research include transition metal oxides, polyanionic compounds, and Prussian blue analogues (PBAs), each exhibiting distinct characteristics in terms of crystal structure and electrochemical performance. Transition metal oxides have attracted significant research interest owing to their high specific capacity, while polyanionic compounds are known for their excellent structural stability and operating voltage. PBAs, on the other hand, have gained considerable attention due to their open framework structure and simple synthesis process. In recent years, modification strategies such as nanostructure engineering, surface coating, and elemental doping have significantly enhanced the electrochemical performance of these cathode materials. Future research should focus on addressing critical scientific challenges, including low intrinsic electronic conductivity and poor interfacial stability, while also exploring novel composite cathode material systems to facilitate the practical application of sodium-ion batteries.

Inorganics doi: 10.3390/inorganics14030071

Authors: Weiqiang Li Dan Wang Wei Zhao Xiangping Zhu Yongning He Guohe Zhang

The versatile surface reconstruction mechanisms, tunable surface properties, and exceptional electron emission characteristics of SrTiO3 films have garnered significant research interest. In this study, SrTiO3 films were synthesized on n-Si(100) substrates via radio frequency magnetron sputtering. To evaluate the impact of thermal annealing, the as-deposited films underwent post-deposition annealing in an oxygen ambient at 600 °C, 800 °C, and 1000 °C for a duration of 2 h each. The structural, chemical, and secondary electron emission (SEE) characteristics of the SrTiO3 films were characterized as a function of their high thermal process. Post-deposition annealing induced a significant improvement in crystallinity, which directly correlated with a heightened SEE yield (SEY). Furthermore, composition analysis revealed a marked stoichiometric reconfiguration at the surface, with the Sr:Ti:O ratio evolving from 1:0.32:1.14 to 1:0.22:0.94, suggesting a move toward an Sr-O terminated surface. The Sr-O terminated surface inherent to these SrTiO3 films promotes efficient electron escape due to its reduced work function. Following a 1000 °C annealing process, the peak SEY undergoes a significant shift from 2.11 to 2.76, representing a thermal optimization of the SEE performance by approximately 30.8%. High-temperature annealing enhances the SEE performance of SrTiO3 films, validating their significant potential for electron multiplication applications. This study provides a scalable pathway for developing highly efficient SEE materials with optimized crystalline and surface properties.

Inorganics doi: 10.3390/inorganics14030070

Authors: Qiuqin Wang Jinlei Wang Chao Feng Jinlong Ge Dazhang Wang Dong Wang Cuishuan Xu

The degradation of aquatic pollutants using eco-friendly and non-toxic photocatalytic materials is a pivotal strategy for water pollution remediation. However, single-component photocatalysts typically suffer from low photocatalytic efficiency due to limited light absorption spectra and rapid recombination of photogenerated charge carriers. This study reports a novel and facile one-step mixing strategy for realizing triple synergistic modifications: heterostructured composite construction, specific surface area regulation, and efficient photogenerated electron–hole pair separation of Bi2MoO6 (BMO) via composite enhancement with low-cost and intrinsically green g-C3N4 (CN), which avoids the high cost, complex processes, and potential pollution risks of precious metal/heavy metal modification for BMO. Under visible-light irradiation, the BMO composite modified with 15 wt% CN achieved a dye removal rate of 85.1% within 60 min, representing a 1.6-fold enhancement in photocatalytic performance compared with that achieved using pristine BMO. We further clarify the unique photocatalytic mechanism of the CN/BMO heterojunction via radical quenching experiments, identifying photogenerated holes (h+) and superoxide radicals (·O2−) as the dominant active species for Rhodamine B (RhB) degradation. This study systematically demonstrates a scalable photocatalyst preparation method that integrates controllable specific surface area, rational heterostructure construction, and simple operation, and we provide an in-depth investigation into the photocatalytic reaction process and underlying synergistic enhancement mechanism. The proposed non-metallic modification route provides a new theoretical and experimental basis for the design of high-efficiency BMO-based photocatalysts, and the as-prepared CN/BMO composite holds great potential for practical application in sustainable solar-driven water purification.

Inorganics doi: 10.3390/inorganics14030069

Authors: Soad S. Alzahrani

The presence of antibiotics in aquatic systems presents significant ecological and health risks. Herein, Fe3O4/MgAl2O4 (MgFeAl-1), 2.5%NiO@Fe3O4/MgAl2O4 (MgFeAl-2), 5%NiO@Fe3O4/MgAl2O4 (MgFeAl-3), and 10%NiO@Fe3O4/MgAl2O4 (MgFeAl-4) were synthesized, selecting glucose as a capping agent, and 600 °C as calcination temperature. The TEM, EDX, BET, XRD, and FTIR techniques were employed to characterize the preidentified sorbents. The average size of MgFeAl-1, MgFeAl-2, MgFeAl-3, and MgFeAl-4 was about 6.53, 5.0, 7.61, and 10.52 nm, respectively, and they exhibited surface areas of 114.15, 154.02, 153.36, and 128.54 m2 g−1, respectively. The sorbents were tested for the removal of ciprofloxacin (CFCN) from aqueous solutions using the batch protocol. The MgFeAl-2 exhibited the highest performance, achieving an adsorption capacity of 99.45 mg g−1, and the sorption equilibrium was reached within 60 min. The pseudo-second-order model best described CFCN sorption onto MgFeAl-2, and liquid-film diffusion influenced CFCN sorption. The CFCN adsorption onto MgFeAl-2 was well represented by the Langmuir isotherm model (R2 = 0.93), indicating a monolayer adsorption. The thermodynamic results indicated a spontaneous, endothermic sorption process. A four-cycle MgFeAl-2 reusability study showed an average efficiency of 90%. Notably, MgFeAl-2 was effective in treating natural-water matrices, with a slight reduction in seawater due to ionic interference. The findings highlight the potential of MgFeAl-2 as an affordable and reusable adsorbent for removing antibiotics from contaminated water.