Inorganics

23 pages, 3154 KiB

Open AccessArticle

Structurally Characterized Cobalt and Nickel Complexes of Flavonoid Chrysin as Potential Radical Scavenging Compounds

by Eleftherios Halevas, Barbara Mavroidi, Despoina Varna, Georgia Zahariou, George Litsardakis, Maria Pelecanou and Antonios G. Hatzidimitriou

Inorganics 2025, 13(7), 230; https://doi.org/10.3390/inorganics13070230 - 7 Jul 2025

Abstract

Polyphenolic compounds, such as flavonoids, possess important structural and physico-chemical characteristics that in combination with their biological properties render them an important class of natural compounds with medicinal prospects. Chrysin is a well-known flavone with antioxidant activity and a multitude of other beneficial [...] Read more.

Polyphenolic compounds, such as flavonoids, possess important structural and physico-chemical characteristics that in combination with their biological properties render them an important class of natural compounds with medicinal prospects. Chrysin is a well-known flavone with antioxidant activity and a multitude of other beneficial properties. The potential of flavonoids to coordinate with metal ions leads to derivatives with enhanced biological profile. Within this framework, four novel heteroleptic complexes of cobalt and nickel with chrysin and the aromatic bidentate chelating agents 2,2′-bipyridine and 1,10-phenanthroline were synthesized, as well as physico-chemically and structurally characterized. The in vitro antioxidant efficiency of the synthesized complexes was examined via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. All complexes showed notable radical scavenging capacity comparable to that of ascorbic acid, providing the incentive for further investigation of their therapeutic potential. Full article

(This article belongs to the Special Issue Metal Complexes Containing Bioactive Ligands: Structure and Biological Evaluation)

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12 pages, 4610 KiB

Open AccessArticle

Phenyl–Pentafluorophenyl Interaction-Mediated Ir(C^N)₂(N^N)-(Ni-Metallacycle) Dual Catalysis for Light-Driven C-S Cross-Coupling Synthesis

by Jun-Feng Chen, Zhan-Xin Zhang, Jing Li and Sheng-Li Huang

Inorganics 2025, 13(7), 229; https://doi.org/10.3390/inorganics13070229 - 7 Jul 2025

Abstract

In many photocatalytic systems employing dual catalysts, researchers often focus primarily on the individual performance of each catalyst while overlooking potential inter-catalyst interactions. In this work, we have developed an efficient dual-catalytic system for C-S cross-coupling reactions, utilizing Ir(C^N)₂(N^N) photosensitizers (PSs) [...] Read more.

In many photocatalytic systems employing dual catalysts, researchers often focus primarily on the individual performance of each catalyst while overlooking potential inter-catalyst interactions. In this work, we have developed an efficient dual-catalytic system for C-S cross-coupling reactions, utilizing Ir(C^N)₂(N^N) photosensitizers (PSs) in conjunction with Ni₃Ce metallacycles. By incorporating specifically designed ligands, we established phenyl–pentafluorophenyl interaction between the photosensitizer and the Ni₃Ce metallacycle. Comparative experiments revealed that systems featuring this interaction exhibited superior catalytic performance. Furthermore, transient fluorescence studies demonstrated that the phenyl–pentafluorophenyl interaction extends the lifetime of the excited state of the photosensitizer. The primary objective of this work is to provide some references and inspiration for the development of dual-catalytic systems. Full article

(This article belongs to the Section Coordination Chemistry)

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22 pages, 1664 KiB

Open AccessArticle

Combination of Acid and Base Activation of Montmorillonite Clay and Its Impact on the Basic Blue-41 Removal Properties: Regeneration and Single Batch Design

by Thamer S. Alraddadi, Rawan Al-Faze, Saheed A. Popoola, Mohd Gulfam Alam, Souad Rakass, Hmoud Al Dmour and Fethi Kooli

Inorganics 2025, 13(7), 228; https://doi.org/10.3390/inorganics13070228 - 7 Jul 2025

Abstract

The treatment with an alkali (sodium hydroxide) solution of acid-activated montmorillonite clay minerals resulted in a reduction in specific surface area. However, a significant enhancement in the removal of basic blue-41 dye solution was achieved compared to acid-activated samples only (first step of [...] Read more.

The treatment with an alkali (sodium hydroxide) solution of acid-activated montmorillonite clay minerals resulted in a reduction in specific surface area. However, a significant enhancement in the removal of basic blue-41 dye solution was achieved compared to acid-activated samples only (first step of activation) and to the raw montmorillonite clay. The obtained products were characterized using different techniques. The results indicated that the acid-activated montmorillonites exhibited different physicochemical properties than the starting raw montmorillonite, with a reduction in the cation exchange capacity and improvements in the specific surface area (from 5 m²/g to 274 m²/g) and total pore volume (from 0.031 cm³/g to 0.450 cm³/g) due to the formation of the amorphous silica phase. However, the treatment with NaOH solution was accompanied by significant reductions in the specific surface area (from 274 m²/g to 18 m²/g) and total pore volume (from 0.450 cm³/g to 0.02 cm³/g) due to the dissolution of the formed amorphous silica phase, as confirmed through ²⁹Si MAS NMR and FTIR techniques. In addition, the SiO₂/Al₂O₃ molar ratios were close to those of the starting montmorillonite clay. The removal of the cationic basic blue-41 was optimized under different conditions, such as different initial concentrations, adsorbent doses, and pHs of the dye solution. The maximum removal capacities of acid-activated clays were in the range of 45 mg/g to 80 mg/g and decreased with the extent of the acid activation process. However, the capacities were enhanced after NaOH treatment and reached values in the range of 80 to 120 mg/g. Enhancing the surface area had less of an impact on the materials’ removal ability. The obtained materials performed well in seven adsorption–regeneration cycles, showing a 70% reduction in removal effectiveness. Full article

(This article belongs to the Section Inorganic Materials)

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15 pages, 11349 KiB

Open AccessArticle

Three-Dimensional Bi-Enriched Bi₂O₃/Bi₂MoO₆ Z-Scheme Heterojunction: Augmented Photocatalytic Phenol Degradation

by Congyu Cai, Shuwen Wang, Pingping Wan, Haoying Cai, Minhui Pan and Weiwei Wang

Inorganics 2025, 13(7), 227; https://doi.org/10.3390/inorganics13070227 - 6 Jul 2025

Abstract

A three-dimensional Bi-enriched Bi₂O₃/Bi₂MoO₆ Z-scheme heterojunction photocatalyst was successfully synthesized via a facile one-step hydrothermal method for efficient phenol degradation under visible light. Structural and morphological characterizations (SEM, TEM, and XRD) confirmed the formation of a [...] Read more.

A three-dimensional Bi-enriched Bi₂O₃/Bi₂MoO₆ Z-scheme heterojunction photocatalyst was successfully synthesized via a facile one-step hydrothermal method for efficient phenol degradation under visible light. Structural and morphological characterizations (SEM, TEM, and XRD) confirmed the formation of a nanoflower-like architecture with a high specific surface area of 81.27 m²/g. Optical and electrochemical analyses revealed efficient charge separation and extended visible-light response. Under visible-light irradiation (λ > 420 nm), this heterojunction (Bi₂O₃:Bi₂MoO₆ = 3:7) demonstrated exceptional performance, degrading 97.06% of phenol (30 mg/L) within 60 min. XPS analysis confirmed the Z-scheme charge transfer mechanism: Photogenerated electrons in the conduction band of Bi₂O₃ (−0.59 eV) facilitated the generation of ·O₂⁻ radicals, while holes in the valence band of Bi₂MoO₆ (2.44 eV) predominantly produced ·OH radicals. This synergistic effect resulted in highly efficient mineralization and degradation of phenol. Full article

(This article belongs to the Special Issue Advances in Inorganic–Organic Composite Photocatalysts for Energy and Environmental Applications)

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18 pages, 831 KiB

Open AccessArticle

New QSPR/QSAR Models for Organic and Inorganic Compounds: Similarity and Dissimilarity

by Alla P. Toropova, Andrey A. Toropov, Alessandra Roncaglioni and Emilio Benfenati

Inorganics 2025, 13(7), 226; https://doi.org/10.3390/inorganics13070226 - 4 Jul 2025

Abstract

Background: We studied in silico models of both organic and inorganic substances. In most cases, these in silico models are used for organic substances only. The following endpoints were taken for the case studies: the octanol–water coefficient (three models), the enthalpies of formation [...] Read more.

Background: We studied in silico models of both organic and inorganic substances. In most cases, these in silico models are used for organic substances only. The following endpoints were taken for the case studies: the octanol–water coefficient (three models), the enthalpies of formation of organometallic compounds, and rat acute toxicity. Methods: The correlation weights were optimized using the Monte Carlo method with two special training and validation sets. The training set was structured into three subsets of active and passive training, as well as a calibration set. The division into these four subsets was carried out using the Las Vegas algorithm. It is assumed that considering groups of different splits into these four subsets is more informative than considering only a single split. Results: Models were built for the octanol–water coefficient for a set containing organic and inorganic substances or for a subset of the original data; other models were developed for a set containing only specially defined inorganic substances for platinum complexes. In addition, models of the enthalpy of formation and for toxicity in rats were built using the same approach for two sets of inorganic substances. Conclusions: A comparison of different methods for the optimization of correlation weights using the Monte Carlo method showed that optimization can be improved using the coefficient of conformism of a correlative prediction (CCCP) or the index of the ideality of correlation (IIC). Optimization with CCCP was the best option for the models of the octanol–water partition coefficient for the set of organic compounds, the octanol–water partition coefficient of the inorganic set, and the enthalpy of formation of the inorganic compounds. However, optimization with IIC was the best option in terms of the toxicity of the inorganic compounds in rats. Full article

(This article belongs to the Special Issue State-of-the-Art Inorganic Chemistry in Italy)

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30 pages, 5199 KiB

Open AccessReview

Modification Strategies of g-C₃N₄-Based Materials for Enhanced Photoelectrocatalytic Degradation of Pollutants: A Review

by Yijie Zhang, Peng Lian, Xinyu Hao, Li Zhang, Lihua Yang, Li Jiang, Kaiyou Zhang, Lei Liao and Aimiao Qin

Inorganics 2025, 13(7), 225; https://doi.org/10.3390/inorganics13070225 - 3 Jul 2025

Abstract

Graphite carbon nitride (g-C₃N₄) is a low band gap non-metallic polymer semiconductor that has broad application prospects and is an ideal material for absorbing visible light, as g-C₃N₄ materials have strong oxidation properties and are easy [...] Read more.

Graphite carbon nitride (g-C₃N₄) is a low band gap non-metallic polymer semiconductor that has broad application prospects and is an ideal material for absorbing visible light, as g-C₃N₄ materials have strong oxidation properties and are easy to modify. The structure formation of g-C₃N₄-based materials makes a series of photocatalytic synthesis reactions possible and improves photocatalytic reaction activity. In this paper, the development history, structures, and performance of g-C₃N₄ are briefly introduced, and the modification strategies of g-C₃N₄ are summarized to improve its photocatalytic and photoelectric catalytic properties via doping, heterojunction construction, etc. The light absorption and utilization of the catalysts are also analyzed in terms of light source conditions, and the application of g-C₃N₄ and its modified materials in photocatalysis and photocatalytic degradation is reviewed. Full article

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17 pages, 2409 KiB

Open AccessArticle

Synthesis of Physically Activated Carbons from Vitellaria paradoxa Shells for Supercapacitor Electrode Applications

by Joshua Atta Alabi, Neda Nazari, Daniel Nframah Ampong, Frank Ofori Agyemang, Mark Adom-Asamoah, Richard Opoku, Rene Zahrhuber, Christoph Unterweger and Kwadwo Mensah-Darkwa

Inorganics 2025, 13(7), 224; https://doi.org/10.3390/inorganics13070224 - 2 Jul 2025

Abstract

This study investigates the processing of shea nut shells (SNSs), an abundant agricultural waste, into porous activated carbon for supercapacitor electrodes through a two-stage thermal treatment involving pyrolysis and physical activation with CO₂ and steam. The aim was to develop sustainable, high-performance [...] Read more.

This study investigates the processing of shea nut shells (SNSs), an abundant agricultural waste, into porous activated carbon for supercapacitor electrodes through a two-stage thermal treatment involving pyrolysis and physical activation with CO₂ and steam. The aim was to develop sustainable, high-performance electrode materials while addressing waste management. Carbonization followed by activation yielded 16.5% (CO₂) and 11.3% (steam) activation yields, with total yields of 4.3% and 2.9%, respectively. CO₂ activation produced carbon (AC_CO₂) with a specific surface area (S_BET) of 1528 m² g⁻¹ and a total pore volume of 0.72 cm³ g⁻¹, a graphitization degree (I_D/I_G = 1.0), and low charge transfer resistance (9.05 Ω), delivering a specific capacitance of 47.5 F g⁻¹ at 0.5 A g⁻¹, an energy density of 9.5 Wh kg⁻¹ at 299 W kg⁻¹, and a fast discharge time of 2.10 s, ideal for power-intensive applications. Steam activation yielded carbon (AC_H₂O) with a higher specific surface area (1842 m² g⁻¹) and pore volume (1.57 cm³ g⁻¹), achieving a superior specific capacitance of 102.2 F g⁻¹ at 0.5 A g⁻¹ and a power density of 204 W kg⁻¹ at 9.2 Wh kg⁻¹, suited for energy storage. AC_CO₂ also exhibited exceptional cyclic stability (90% retention after 10,000 cycles). These findings demonstrate SNS-derived activated carbon as a versatile, eco-friendly material, with CO₂ activation optimizing power delivery and steam activation enhancing energy capacity, offering tailored solutions for supercapacitor applications and sustainable waste utilization. Full article

(This article belongs to the Special Issue Carbon-Based Hybrid Materials for Environmental and Energy Applications)

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20 pages, 3492 KiB

Open AccessArticle

Microstructure and Electrochemical Properties of Pure and Vanadium-Doped Li₄Ti₅O₁₂ Nanoflakes for High Performance Supercapacitors

by Mudda Deepak, Obili M. Hussain and Christian M. Julien

Inorganics 2025, 13(7), 223; https://doi.org/10.3390/inorganics13070223 - 1 Jul 2025

Abstract

Nanostructured binary metal oxides have demonstrated the potential for increased electrochemical performance due to their structural stability, electronic conductivity, and various oxidation states. The Li₄Ti₅O₁₂ was successfully synthesized via a hydrothermal procedure at different reaction periods (12, 18, [...] Read more.

Nanostructured binary metal oxides have demonstrated the potential for increased electrochemical performance due to their structural stability, electronic conductivity, and various oxidation states. The Li₄Ti₅O₁₂ was successfully synthesized via a hydrothermal procedure at different reaction periods (12, 18, and 24 h), and its microstructural and supercapacitive characteristics were studied. The XRD and XPS studies confirm the formation of Li₄Ti₅O₁₂ in pure phase when synthesized at 24 h (LTO@24) of reaction time. FESEM and HRTEM images reveal nanoflake surface morphology. Both LTO@24 and V-LTO@24 nanoflakes exhibited impressive electrochemical performance, with specific capacitance values of 357 and 442 F g^−1, respectively, at 1 A g⁻¹. The V-LTO@24 showed remarkable supercapacitor properties, demonstrating excellent rate capability and cycleability that surpass those of pure LTO@24. Full article

(This article belongs to the Special Issue Novel Research on Electrochemical Energy Storage Materials)

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17 pages, 3368 KiB

Open AccessArticle

Enhanced Photocatalytic Performances and Mechanistic Insights for Novel Ag-Bridged Dual Z-Scheme AgI/Ag₃PO₄/WO₃ Composites

by Chunlei Ma, Jianke Tang, Qi Wang, Rongqian Meng and Qiaoling Li

Inorganics 2025, 13(7), 222; https://doi.org/10.3390/inorganics13070222 - 1 Jul 2025

Abstract

In this study, AgI/Ag₃PO₄/WO₃ ternary composite photocatalysts with dual Z-scheme heterojunction were fabricated via the in situ loading of Ag₃PO₄ onto WO₃ followed by anion exchange. Compared to single photocatalysts and binary composites, the [...] Read more.

In this study, AgI/Ag₃PO₄/WO₃ ternary composite photocatalysts with dual Z-scheme heterojunction were fabricated via the in situ loading of Ag₃PO₄ onto WO₃ followed by anion exchange. Compared to single photocatalysts and binary composites, the AgI/Ag₃PO₄/WO₃ composites exhibited enhanced photocatalytic activity in the photodegradation of chlortetracycline hydrochloride (CTC) under visible-light irradiation. Notably, the AAW-40 photocatalyst, which contained an AgI/Ag₃PO₄ molar ratio of 40%, degraded 75.7% of the CTC within 75 min. Moreover, AAW-40 demonstrated an excellent performance in the cyclic degradation of CTC over four cyclic degradation experiments. The separation and transfer kinetics of the AgI/Ag₃PO₄/WO₃ composite were investigated with photoluminescence spectroscopy, time-resolved photoluminescence spectroscopy, and electrochemical measurements. The improved photocatalytic performance was primarily due to the creation of a silver-bridged dual Z-scheme heterojunction, which facilitated the efficient separation of photoinduced electron–hole pairs, retained the strong reducing capability of electrons in AgI, and ensured the strongly oxidizing nature of the photoexcited holes in WO₃. The dual Z-scheme charge-transfer mechanism was further validated using in situ X-ray photoelectron spectroscopy. This study provides a foundation for developing innovative dual Z-scheme photocatalytic systems aimed at the efficient degradation of antibiotics in wastewater. Full article

(This article belongs to the Special Issue Inorganic Photocatalysts for Environmental Applications)

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21 pages, 2880 KiB

Open AccessReview

Italian Contribution to the Recent Growth of the Luminescent 1,3-Bis(Pyridin-2-yl)benzene Platinum(II) Complex Family

by Alessia Colombo, Claudia Dragonetti, Francesco Fagnani, Daniele Marinotto and Dominique Roberto

Inorganics 2025, 13(7), 221; https://doi.org/10.3390/inorganics13070221 - 1 Jul 2025

Abstract

The first chlorido platinum(II) complex with a cyclometallated 1,3-bis(pyridin-2-yl)benzene ligand, Pt(bpyb)Cl, was prepared in 1999. Four years later, its luminescent properties were discovered. Since then, a huge number of studies have been dedicated to the synthesis and characterization of related complexes, and to [...] Read more.

The first chlorido platinum(II) complex with a cyclometallated 1,3-bis(pyridin-2-yl)benzene ligand, Pt(bpyb)Cl, was prepared in 1999. Four years later, its luminescent properties were discovered. Since then, a huge number of studies have been dedicated to the synthesis and characterization of related complexes, and to their application in photonics, optoelectronics, bioimaging, and photodynamic therapy. The present review concerns the main results obtained in the last five years by our research group in Milan. After a brief introduction on Pt(bpyb)Cl complexes, we illustrate our recent investigations to show the Milanese contribution to the rapid growth of this platinum family. Full article

(This article belongs to the Special Issue State-of-the-Art Inorganic Chemistry in Italy)

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14 pages, 3131 KiB

Open AccessArticle

New Complex of Salinomycin with Hg(II)—Synthesis and Characterization

by Juliana Ivanova, Irena Pashkunova-Martic, Johannes Theiner, Nikola Burdzhiev, Peter Dorkov and Ivo Grabchev

Inorganics 2025, 13(7), 220; https://doi.org/10.3390/inorganics13070220 - 1 Jul 2025

Abstract

Salinomycin is a polyether ionophorous antibiotic with promising antineoplastic properties. Published studies have revealed that the compound also exerts pronounced antidotal activity against cadmium (Cd) and lead (Pb) intoxications. It has been proven that salinomycin with Cd(II) forms a coordination compound of a [...] Read more.

Salinomycin is a polyether ionophorous antibiotic with promising antineoplastic properties. Published studies have revealed that the compound also exerts pronounced antidotal activity against cadmium (Cd) and lead (Pb) intoxications. It has been proven that salinomycin with Cd(II) forms a coordination compound of a composition [Cd(C₄₂H₆₉O₁₁)₂(H₂O)₂] and an octahedral molecular geometry, while the coordination compound of the antibiotic with Pb(II) has a square pyramidal structure and composition [Pb(C₄₂H₆₉O₁₁)(NO₃)]. To date, there is no published information about the ability of salinomycin to form complexes with the mercury ion (Hg(II)). Herein, we report, for the first time, a synthetic procedure for a complex compound of salinomycin with Hg(II). The coordination compound was characterized by a variety of methods, such as elemental analysis, attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR), electrospray ionization–mass spectrometry (ESI-MS), powder X-ray diffraction, nuclear magnetic resonance spectroscopy (NMR), thermogravimetry with differential thermal analysis (TG-DTA), and thermogravimetry with mass spectrometry (TG-MS). The elemental analysis data revealed that the new compound is of the chemical composition [Hg(C₄₂H₆₉O₁₁)(H₂O)(OH)]. Based on the results from the spectral analyses, the most probable structure of the complex was proposed. Full article

(This article belongs to the Section Coordination Chemistry)

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42 pages, 6704 KiB

Open AccessReview

An Introduction to the Role of Molybdenum and Tungsten in Biology

by Helder M. Marques

Inorganics 2025, 13(7), 219; https://doi.org/10.3390/inorganics13070219 - 1 Jul 2025

Abstract

This short review provides an overview of the bioinorganic chemistry of molybdenum and tungsten, offering insights into current research perspectives and fundamental concepts in the field, as well as gaps in our knowledge. It is designed to highlight areas where future research is [...] Read more.

This short review provides an overview of the bioinorganic chemistry of molybdenum and tungsten, offering insights into current research perspectives and fundamental concepts in the field, as well as gaps in our knowledge. It is designed to highlight areas where future research is needed to fully elucidate the mechanisms of molybdenum- and tungsten-dependent enzymes and their broader significance in biochemistry and bioinorganic chemistry. It also provides an accessible introduction for senior undergraduate students and novice postgraduate researchers who are new to the field of bioinorganic chemistry. Towards this end, illustrative examples are presented, showcasing the essential roles these metals play in biological systems, their coordination chemistry, and their catalytic functions in metalloenzymes. Full article

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24 pages, 1906 KiB

Open AccessArticle

Coupling Advanced Oxidation and Anaerobic Treatment for Landfill Leachate: Magnetite-Catalyzed Ozone and USAB Reactor Efficiency

by Dorance Becerra-Moreno, Antonio Zuorro, Fiderman Machuca-Martínez, Luisa F. Ramírez-Rios, Janet B. García-Martínez and Andrés F. Barajas-Solano

Inorganics 2025, 13(7), 218; https://doi.org/10.3390/inorganics13070218 - 30 Jun 2025

Abstract

Sanitary landfill leachate treatment was evaluated using magnetite-catalyzed ozone, an upflow anaerobic sludge blanket (UASB) reactor, and microalgae, both individually and in combination, to improve biodegradability and remove organic matter, solids, metals, and nutrients. Leachates were characterized before and after each treatment, and [...] Read more.

Sanitary landfill leachate treatment was evaluated using magnetite-catalyzed ozone, an upflow anaerobic sludge blanket (UASB) reactor, and microalgae, both individually and in combination, to improve biodegradability and remove organic matter, solids, metals, and nutrients. Leachates were characterized before and after each treatment, and their impacts on methanogenic activity, aerobic toxicity, and the BOD₅/COD ratio were assessed. Magnetite-catalyzed ozone pretreatment enhanced biodegradability, enabling an optimal coupling point with the UASB at 40 min when the specific methanogenic activity reached 0.22 g CH₄-COD/(gVSS·d). The UASB achieved COD removal rates of up to 75%, but high concentrations were maintained in the effluent with low ammoniacal nitrogen and phosphorus removal rates. Microalgae promoted nutrient removal, reducing total nitrogen and phosphorus by up to 65% and 70%, respectively, although with lower efficiency in terms of organic matter removal. Process coupling demonstrated that ozonation followed by UASB application improved anaerobic degradation, whereas the use of microalgae after biological treatment optimized the final effluent quality. Despite the improvements achieved, the final values for some parameters still exceeded the discharge limits, indicating the need for operational adjustments or additional treatments to ensure effective purification. Full article

(This article belongs to the Special Issue Transition Metal Catalysts: Design, Synthesis and Applications)

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13 pages, 3753 KiB

Open AccessArticle

Highly Transparent Yb:Y₂O₃ Laser Ceramics with High Thermal Conductivity Obtained via a Sintering-Additive-Free Strategy

by Zhongchao Fu, Qiang Wu, Nan Wu, Haibo Long, Jinsheng Li, Yi Ren and Zhaoxia Hou

Inorganics 2025, 13(7), 217; https://doi.org/10.3390/inorganics13070217 - 27 Jun 2025

Abstract

Fine-grained Yb:Y₂O₃ laser ceramics with excellent transmittance and thermal conductivity were fabricated from commercial powders. The process involved aqueous colloidal forming, additive-free air pre-sintering at 1400 °C, and hot isostatic pressing at 1550 °C. Suspensions were prepared with a deionization [...] Read more.

Fine-grained Yb:Y₂O₃ laser ceramics with excellent transmittance and thermal conductivity were fabricated from commercial powders. The process involved aqueous colloidal forming, additive-free air pre-sintering at 1400 °C, and hot isostatic pressing at 1550 °C. Suspensions were prepared with a deionization process to alleviate the hydrolysis issue, which optimizes the microstructure uniformity and enhances the green compacts’ density after consolidation. The microstructure, in-line transmittance, microhardness, and fracture toughness of the Yb³⁺-doped Y₂O₃ ceramics with different concentrations were measured. The 5.0 at% Yb³⁺-doped Y₂O₃ ceramic yielded a superior transmittance of 80.1% at 1100 nm and 83.0% in the mid-infrared region. The average grain size was 752 nm. The sample exhibited a thermal conductivity of 9.94 W·m⁻¹·K⁻¹ while achieving a 1076 nm laser output with a 42 mW peak power and 4.3% slope efficiency. Full article

(This article belongs to the Special Issue Preparation and Application of Transparent Ceramics)

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15 pages, 1856 KiB

Open AccessArticle

Eskebornite CuFeSe₂: Solid-State Synthesis and Thermoelectric Properties

by Se-Hyeon Choi and Il-Ho Kim

Inorganics 2025, 13(7), 216; https://doi.org/10.3390/inorganics13070216 - 27 Jun 2025

Abstract

Eskebornite (CuFeSe₂), a member of the I–III–VI₂ ternary semiconductor family, was explored in this study as a potential thermoelectric material, offering new insights into its synthesis, structural characteristics, and transport behavior. Structurally analogous to chalcopyrite (CuFeS₂)—an extensively studied [...] Read more.

Eskebornite (CuFeSe₂), a member of the I–III–VI₂ ternary semiconductor family, was explored in this study as a potential thermoelectric material, offering new insights into its synthesis, structural characteristics, and transport behavior. Structurally analogous to chalcopyrite (CuFeS₂)—an extensively studied antiferromagnetic semiconductor—eskebornite remains relatively underexplored, particularly regarding its solid-state synthesis and thermoelectric performance. To address this gap, pure eskebornite was synthesized via mechanical alloying followed by hot pressing, a method that enables the fine control of its phase composition and microstructural features. The synthesized undoped CuFeSe₂ exhibited p-type nondegenerate semiconducting behavior, with electrical conductivity increasing monotonically over the temperature range of 323–623 K, indicative of thermally activated carrier transport. Simultaneously, a decreasing trend in thermal conductivity with temperature was observed, likely resulting from intensified phonon scattering, which serves to suppress heat transport and enhance the thermoelectric efficiency by maintaining a thermal gradient across the material. A peak in the Seebeck coefficient occurred between 473 and 523 K, suggesting the onset of intrinsic carrier excitation and a transition in dominant carrier transport mechanisms. The material exhibited a maximum power factor of 1.55 μWm⁻¹K⁻², while the dimensionless thermoelectric figure of merit (ZT) reached a peak value of 0.37 × 10⁻³ at 523 K. Although the ZT remains low, these results underscore the potential of eskebornite as a thermoelectric candidate, with substantial room for optimization through chemical doping, microstructural engineering, or nanostructuring approaches to enhance the carrier mobility and reduce the lattice thermal conductivity. Full article

(This article belongs to the Special Issue Advances in Thermoelectric Materials, 2nd Edition)

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17 pages, 2959 KiB

Open AccessArticle

[Pd(dach)Cl₂] Complex Targets Proteins Involved in Ribosomal Biogenesis, and RNA Splicing in HeLa Cells

by Vanja Ralić, Katarina Davalieva, Branislava Gemović, Milan Senćanski, Maja D. Nešić, Jelena Žakula, Milutin Stepić and Marijana Petković

Inorganics 2025, 13(7), 215; https://doi.org/10.3390/inorganics13070215 - 26 Jun 2025

Abstract

This study aims to investigate the effect of the Pd(II) complex on HeLa cells using computational biology and proteomic analysis. [Pd(dach)Cl₂]-treated HeLa cells were subjected to comparative proteomics analysis using label-free data-independent liquid chromatography-tandem mass spectrometry (LC-MS/MS). In parallel, [...] Read more.

This study aims to investigate the effect of the Pd(II) complex on HeLa cells using computational biology and proteomic analysis. [Pd(dach)Cl₂]-treated HeLa cells were subjected to comparative proteomics analysis using label-free data-independent liquid chromatography-tandem mass spectrometry (LC-MS/MS). In parallel, the informational spectrum method (ISM) was used to predict potential protein interactors of the [Pd(dach)Cl₂] complex in HeLa cells. Proteomics analysis revealed 121 differentially abundant proteins (DAPs). Enrichment analysis of Gene Ontology (GO) annotations revealed ATP hydrolysis and RNA/protein binding as the top molecular functions and RNA splicing and protein–RNA complex organization as the top biological processes. Enrichment analysis of altered canonical pathways pointed out spliceosome and ribosome pathways. The top hub proteins with potential regulatory importance encompassed ribosomal proteins, translational and transcriptional factors, and components of the ribosome assembly machinery. ISM and cross-spectral analysis identified the nucleoplasm and sensor of the single-stranded DNA (SOSS DNA) complex. Proteome analysis showed that [Pd(dach)Cl₂] targets proteins involved in ribosomal biogenesis and RNA splicing, whereas theoretical prediction implies also potential effect on p53 signaling pathway, and thus, alterations of the expression of regulatory proteins involved in cell survival and proliferation. These findings underscore the potential of Pd(II) complexes as anti-cancer agents, warranting further exploration and detailed functional validation. Full article

(This article belongs to the Special Issue Metal Complexes Diversity: Synthesis, Conformations, and Bioactivity)

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14 pages, 2008 KiB

Open AccessArticle

A Unique Trinuclear, Triangular Ni(II) Complex Composed of Two tri-Anionic bis-Oxamates and Capping Nitroxyl Radicals

by Vitaly A. Morozov, Denis G. Samsonenko and Kira E. Vostrikova

Inorganics 2025, 13(7), 214; https://doi.org/10.3390/inorganics13070214 - 25 Jun 2025

Abstract

Phenylene-based bis-oxamate polydentate ligands offer a unique opportunity for creating a large variety of coordination compounds, in which paramagnetic metal ions are strongly magnetically coupled. The employment of imino nitroxyl (IN) radicals as supplementary ligands confers numerous benefits, including the strong ferromagnetic interaction [...] Read more.

Phenylene-based bis-oxamate polydentate ligands offer a unique opportunity for creating a large variety of coordination compounds, in which paramagnetic metal ions are strongly magnetically coupled. The employment of imino nitroxyl (IN) radicals as supplementary ligands confers numerous benefits, including the strong ferromagnetic interaction between Ni and IN. Furthermore, the chelating IN can act as a capping ligand, thereby impeding the formation of coordination polymers. In this study, we present the molecular and crystal structure and experimental and theoretical magnetic behavior of an exceptional neutral trinuclear complex [Ni(L³⁻)₂(IN)₃]∙5CH₃OH (1) (L is N,N′-1,3-phenylenebis-oxamic acid; IN is [4,4,5,5-tetramethyl-2-(6-methylpyridin-2-yl)-4,5-dihydro-1H-imidazol-1-yl]oxidanyl radical) with a cyclic triangular arrangement. Moreover, in this compound three Ni²⁺ ions are linked by the two bis-oxamate ligands playing a rare tritopic function due to an unprecedented triple deprotonation of the related meta-phenylene-bis(oxamic acid). The main evidence of such a deprotonation of the ligand is the neutrality of the cluster, since there are no anions or cations compensating for its charge in the crystals of the compound. Despite the presence of six possible magnetic couplings in the trinuclear cluster 1, its behavior was reproduced with a high degree of accuracy using a three-J model and ZFS, under the assumption that the three different Ni-IN interactions are equal to each other, whereas only two equivalent-in-value Ni-Ni interactions were taken into account, with the third one being equated to zero. Our study indicates the presence of two opposite-in-nature types of magnetic interactions within the triangular core. DFT and CASSCF/NEVPT2 calculations were completed to support the experimental magnetic data simulation. Full article

(This article belongs to the Section Coordination Chemistry)

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20 pages, 9373 KiB

Open AccessArticle

In Vitro Antibacterial Activities and Calf Thymus DNA–Bovine Serum Albumin Interactions of Tridentate NNO Hydrazone Schiff Base–Metal Complexes

by Maida Katherine Triviño-Rojas, Santiago José Jiménez-Lopez, Richard D’Vries, Alberto Aragón-Muriel and Dorian Polo-Cerón

Inorganics 2025, 13(7), 213; https://doi.org/10.3390/inorganics13070213 - 25 Jun 2025

Abstract

Their demonstrable bioactive characteristics, coupled with their wide structural diversity and coordination versatility, render Schiff bases and their coordination complexes biologically active compounds demonstrating outstanding properties. This research describes the synthesis and characterization of new Cu(II) and Ni(II) complexes with an NNO-donor hydrazone [...] Read more.

Their demonstrable bioactive characteristics, coupled with their wide structural diversity and coordination versatility, render Schiff bases and their coordination complexes biologically active compounds demonstrating outstanding properties. This research describes the synthesis and characterization of new Cu(II) and Ni(II) complexes with an NNO-donor hydrazone ligand (HL). The crystal structure of the HL ligand was determined through single-crystal X-ray diffraction studies. The in vitro antibacterial activities of the HL ligand and its metal(II) complexes against Gram-positive and Gram-negative bacteria demonstrated that the metal(II) complexes displayed greater antimicrobial activities compared to the free Schiff base ligand. Furthermore, the interaction of the ligand and the complexes with calf thymus DNA (CT-DNA) was explored through electronic absorption and viscosity measurements, suggesting intercalation as the most likely mode of binding. The compounds promoted oxidative DNA cleavage, as demonstrated by the strand breaks of the pmChery plasmid under oxidative stress conditions. Finally, fluorescence spectroscopy also revealed the strong binding affinity of these compounds for bovine serum albumin (BSA). Full article

(This article belongs to the Special Issue Metal-Based Compounds: Relevance for the Biomedical Field, 2nd Edition)

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28 pages, 4032 KiB

Open AccessArticle

Synthesis and Characterization of a Water-Soluble Nanomaterial via Deep Nitration of Light Fullerene C₆₀

by Natalya Kulenova, Marzhan Sadenova, Bagdat Azamatov, Bauyrzhan Maratuly, Nikolay Charykov, Mikhail Arshinov and Nail Beisekenov

Inorganics 2025, 13(7), 212; https://doi.org/10.3390/inorganics13070212 - 24 Jun 2025

Abstract

A direct non-catalytic synthesis of a new water-soluble polynitro-hydroxylated fullerene derivative, C₆₀(NO₂)₁₈(OH)₂, was carried out using a mixture of concentrated nitric and sulfuric acids. The resulting poly-nitro adduct was comprehensively characterized by elemental C-H-N analysis, [...] Read more.

A direct non-catalytic synthesis of a new water-soluble polynitro-hydroxylated fullerene derivative, C₆₀(NO₂)₁₈(OH)₂, was carried out using a mixture of concentrated nitric and sulfuric acids. The resulting poly-nitro adduct was comprehensively characterized by elemental C-H-N analysis, energy-dispersive X-ray spectroscopy, infrared (IR) and electron spectroscopy, nuclear magnetic resonance (NMR), high-performance liquid chromatography (HPLC), and thermogravimetric analysis (TGA). A detailed investigation of the physicochemical properties of aqueous solutions of C₆₀(NO₂)₁₈(OH)₂ demonstrated that the synthesized compound is a previously undescribed mixed polynitro-hydroxyl adduct of light fullerene C₆₀, featuring a high degree of nitration (18 nitro groups per fullerene core). The composition and structure of the adduct were confirmed by spectroscopic and refractometric analyses. In terms of redox behavior, the compound exhibits significant reducing and antioxidant properties. These physicochemical characteristics suggest the potential of C₆₀(NO₂)₁₈(OH)₂ for further development as a biocompatible nanomaterial suitable for medical applications. Full article

(This article belongs to the Special Issue Development of Nanocomposite Materials for Environmental Remediation and Biomedical Application)

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