Inorganics

11 pages, 1977 KB

Open AccessArticle

Structural, Up-Conversion Luminescence, and Electron Paramagnetic Resonance Investigations of Yb³⁺/Er³⁺-Doped LiGdF₄ Nanocrystals Dispersed in Silica Glassy Matrix

by Corina Secu, Cristian Radu, Arpad Rostas and Mihail Secu

Inorganics 2025, 13(11), 378; https://doi.org/10.3390/inorganics13110378 - 19 Nov 2025

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Abstract

We have investigated the structural, morphological, magnetic, and up-conversion luminescence properties of the Yb³⁺/Er³⁺-doped LiGdF₄ nanocrystals precipitated in the silica glassy matrix. Morphological analysis showed uniform distribution of LiGdF₄ nanocrystals (tens of nm in size), embedded in [...] Read more.

We have investigated the structural, morphological, magnetic, and up-conversion luminescence properties of the Yb³⁺/Er³⁺-doped LiGdF₄ nanocrystals precipitated in the silica glassy matrix. Morphological analysis showed uniform distribution of LiGdF₄ nanocrystals (tens of nm in size), embedded in silica glass matrix. FTIR spectroscopy analysis showed trifluoracetates thermolysis with silica lattice formation and structural analysis by XRD is consistent with the LiGdF₄ crystallization process, most likely through an autocatalytic reaction. The stress and crystalline lattice distortion are assigned to the doping and glass matrix environment where the growth process occurs. The EPR spectra associated with the Gd³⁺ ions have shown a well-defined spectrum in the xerogel, associated with the trifluoroacetate ligand environment. In the LiGdF₄ nanocrystals, the broad and unresolved spectrum is due to an envelope of unresolved anisotropic fine structure and a high dipole–dipole interaction between the Gd³⁺/Yb³⁺/Er³⁺ paramagnetic ions. Under 980 nm laser light pumping, we observed the characteristic “blue”, “green” and “red” up-conversion luminescences of the Er³⁺ ions through Yb → Er energy transfer process, that imply three and two-photon process; near UV up-conversion luminescence of Gd³⁺ is observed at about 280–300 nm where Yb → Er and Er → Gd energy transfer is involved. The UC luminescence properties can be improved up to two times by additional Yttrium co-doping due to the induced crystal field distortion. Full article

(This article belongs to the Special Issue Feature Papers in Inorganic Solid-State Chemistry 2025)

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27 pages, 4687 KB

Open AccessArticle

Reactive Crystallization of Lithium Carbonate from LiCl and Na₂CO₃: Effect of Polyacrylic Acid Monitored by Focused Reflectance Measurement

by Eder Piceros, Ricardo I. Jeldres, Pedro Robles and Teófilo A. Graber

Inorganics 2025, 13(11), 377; https://doi.org/10.3390/inorganics13110377 - 19 Nov 2025

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Abstract

The reactive crystallization of lithium carbonate (Li₂CO₃) from LiCl and Na₂CO₃ solutions was studied by Focused Beam Reflectance Measurement (FBRM) to evaluate the effect of polyacrylic acid (PAA) of different molecular weights (1800, 230,000, and 450,000 [...] Read more.

The reactive crystallization of lithium carbonate (Li₂CO₃) from LiCl and Na₂CO₃ solutions was studied by Focused Beam Reflectance Measurement (FBRM) to evaluate the effect of polyacrylic acid (PAA) of different molecular weights (1800, 230,000, and 450,000 g/mol). In situ monitoring determined nucleation and growth rates, as well as the evolution of fine (<10 µm) and coarse (50–150 µm) particles. It was observed that maximum velocities occur in the first few seconds after mixing, decreasing subsequently due to the consumption of supersaturation. Increasing the initial LiCl concentration intensified nucleation and growth; however, at 4 M, massive nucleation and attrition predominated, resulting in an abundance of fines. Li₂CO₃ spherulites formed under all conditions, becoming more compact at higher LiCl concentrations. The addition of PAA significantly altered their size and morphology: the low-molecular-weight polymer inhibited spherulite formation, while the high-molecular-weight polymers reduced growth and promoted denser and more compact spherulites. SEM micrographs confirmed these trends, highlighting the role of PAA molecular weight as a key parameter modulating the kinetics and morphology of Li₂CO₃ in reactive crystallization processes. Full article

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4 pages, 178 KB

Open AccessEditorial

Metal Complexes with N-Donor Ligands: Second Edition

by László Kótai

Inorganics 2025, 13(11), 376; https://doi.org/10.3390/inorganics13110376 - 18 Nov 2025

Viewed by 278

Abstract

A wide variety of complexes containing N-donor ligands from ammonia, amines, Schiff bases or N-heterocycles have been prepared since the first complex compound of the family, which was an ammonia cobalt complex, was discovered [...] Full article

(This article belongs to the Special Issue Metal Complexes with N-donor Ligands, 2nd Edition)

4 pages, 164 KB

Open AccessEditorial

Inorganic Electrode Materials in High-Performance Energy Storage Devices

by Ting Deng

Inorganics 2025, 13(11), 375; https://doi.org/10.3390/inorganics13110375 - 13 Nov 2025

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Abstract

This special issue focuses on the design, synthesis, optimization, and application of inorganic electrode materials in high-performance energy storage devices, covering lithium–sulfur batteries [...] Full article

(This article belongs to the Special Issue Inorganic Electrode Materials in High-Performance Energy Storage Devices)

10 pages, 1510 KB

Open AccessArticle

Enhanced Gettering of Multicrystalline Silicon Using Nanowires for Solar Cell Applications

by Achref Mannai, Karim Choubani, Wissem Dimassi and Mohamed Ben Rabha

Inorganics 2025, 13(11), 374; https://doi.org/10.3390/inorganics13110374 - 12 Nov 2025

Viewed by 409

Abstract

In this work, we present a gettering technique for multicrystalline silicon (mc-Si) by combining a nanowire structure with thermal treatment under nitrogen in an infrared lamp furnace. The silicon nanowires were elaborated using the Silver Nanoparticles Chemical Etching (Ag-NPsCE) technique. The optimal conditions [...] Read more.

In this work, we present a gettering technique for multicrystalline silicon (mc-Si) by combining a nanowire structure with thermal treatment under nitrogen in an infrared lamp furnace. The silicon nanowires were elaborated using the Silver Nanoparticles Chemical Etching (Ag-NPsCE) technique. The optimal conditions for achieving effective gettering were determined based on the minority carrier lifetime (τ_eff) measurements. The results show τ_eff as a function of the gettering temperature and etching time, both before and after the removal of Ag nanoparticles using HNO₃. In both cases, the surface was identically treated with a 10% HF dip immediately prior to the carrier lifetime measurements. The highest τ_eff value, prior to Ag removal, was obtained after an etching duration of 3 min and was 6 µs at an excess carrier density Δn = 1 × 10¹⁴ cm⁻³. Moreover, τ_eff improves after silver removal. Therefore, removing Ag atoms using an aqueous HNO₃ solution is necessary to prevent this issue. Following Ag nanoparticle removal, τ_eff further increases, reaching 19 µs at a gettering temperature of 850 °C. Similarly, the electrical conductivity (ρ) and carrier mobility (μ) improve significantly after gettering, where the resistivity increases from 5.5 Ω·cm for the reference mc-Si to 1.9 Ω·cm, and the mobility rises from 122 cm²·V⁻¹·s⁻¹ to 253 cm²·V⁻¹·s⁻¹ after nanowire-based gettering at 850 °C. Overall, this method provides a scalable, practical, and cost-effective route to optimize mc-Si for high-performance photovoltaic applications. Full article

(This article belongs to the Special Issue Advanced Inorganic Nanomaterials for Energy Conversion and Catalysis Applications, 2nd Edition)

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13 pages, 2779 KB

Open AccessArticle

Controlled Synthesis of Alkali Metal Hydroxide Particles via Solvothermal Processing

by Chiara Tuccio, Francesco Armetta, Delia Francesca Chillura Martino, Ramūnas Skaudžius and Maria Luisa Saladino

Inorganics 2025, 13(11), 373; https://doi.org/10.3390/inorganics13110373 - 9 Nov 2025

Viewed by 746

Abstract

This study presents a solvothermal approach starting from micron-sized hydroxide precursors, which combines features of top-down size reduction and bottom-up recrystallization, leading to nanoscale hydroxide particles. The method is based on autoclave treatment at a moderate temperature (180 °C) and a pressure of [...] Read more.

This study presents a solvothermal approach starting from micron-sized hydroxide precursors, which combines features of top-down size reduction and bottom-up recrystallization, leading to nanoscale hydroxide particles. The method is based on autoclave treatment at a moderate temperature (180 °C) and a pressure of 8 bar, using different mixtures of water and isopropanol. The hydroxide precursors, used in micrometric form without surfactants or additives, were converted into nanoscale particles through a one-pot, one-step process. The nanomaterials obtained were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), optical microscopy (MO), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) surface area analysis to assess their structural, morphological and textural characteristics. The results show that solvent composition and precursor concentration strongly influence the crystalline phase, particle morphology, dispersion stability and surface area. Well-defined acicular and fibrous morphologies were obtained for Ba(OH)₂ and Sr(OH)₂, while Mg(OH)₂ formed spherical and hexagonal structures, respectively. Of all the conditions tested, the 75:25 water/isopropanol ratio produced the most stable systems. This work provides a method to produce alkaline earth hydroxide nanoparticles with tunable properties. Full article

(This article belongs to the Special Issue Featured Papers in Inorganic Materials 2025)

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29 pages, 2287 KB

Open AccessReview

A Review of Synthesis, Characterization, Properties, and Applications of Double Perovskite Oxides

by Pablo V. Tuza and Mariana M. V. M. Souza

Inorganics 2025, 13(11), 372; https://doi.org/10.3390/inorganics13110372 - 7 Nov 2025

Cited by 1 | Viewed by 898

Abstract

Double perovskites are represented by the formula A₂BB’O₆ and AA’BB’O₆. These materials have been synthesized using the solid-state reaction, sol–gel, Pechini, and hydrothermal methods. X-ray fluorescence, X-ray diffraction, magnetic measurements, transmission electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed reduction, [...] Read more.

Double perovskites are represented by the formula A₂BB’O₆ and AA’BB’O₆. These materials have been synthesized using the solid-state reaction, sol–gel, Pechini, and hydrothermal methods. X-ray fluorescence, X-ray diffraction, magnetic measurements, transmission electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed reduction, synchrotron X-ray diffraction, neutron powder diffraction, extended X-ray absorption fine structure, and Raman spectroscopy have been used for the characterization of double perovskites. X-ray diffraction, synchrotron X-ray diffraction, and neutron powder diffraction coupled with the Rietveld method determine the crystal structure of a sample. These materials present various properties and applications. The present review aims (i) to report a process to determine the symmetry, apparent size, and apparent strain using the Rietveld method; (ii) show how experimental characterization techniques complement each other in the investigation of double perovskites; (iii) describe how the synthesis method can help in the uncovering of double perovskites with improved properties; and (iv) exemplify some of the main applications of double perovskites. Full article

(This article belongs to the Special Issue Recent Progress in Perovskites)

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11 pages, 936 KB

Open AccessArticle

High-Pressure Intrusion of Saline Solutions in Hydrophobic STT-Type Zeosil

by Yacine-Malik Chaib-Draa, Amir Astafan, Gérald Chaplais, Habiba Nouali, Séverinne Rigolet and Andrey Ryzhikov

Inorganics 2025, 13(11), 371; https://doi.org/10.3390/inorganics13110371 - 6 Nov 2025

Viewed by 435

Abstract

High-pressure intrusion of water and LiCl aqueous solutions at different concentrations in hydrophobic STT-type zeosil was studied for possible applications in absorption and storage of mechanical energy. The water is intruded at a pressure of 35 MPa and remains trapped in the pores [...] Read more.

High-pressure intrusion of water and LiCl aqueous solutions at different concentrations in hydrophobic STT-type zeosil was studied for possible applications in absorption and storage of mechanical energy. The water is intruded at a pressure of 35 MPa and remains trapped in the pores after pressure release, which corresponds to bumper behavior with total energy absorption. The use of LiCl solution leads to a change in system behavior, regardless of the concentration investigated (10, 15, or 20 M). Its intrusion is mainly reversible, but a small part of the intruded liquid remains in the pores after the first intrusion–extrusion cycle, which corresponds to a mixed behavior of bumper and shock absorber. The intrusion pressure rises strongly with an increase in salt concentration and reaches 227 MPa for a LiCl 20 M solution; the stored energy of 27 J/g can be achieved. The characterization of STT-type zeosil before and after intrusion–extrusion tests by structural and physicochemical methods shows that silanol defects are formed both under the intrusion of water and LiCl solutions. The relationship between zeosil structure and intrusion–extrusion characteristics is discussed by comparing the results obtained with those of other structural types of zeosils. Full article

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22 pages, 5806 KB

Open AccessArticle

High-Performance Fluoride Removal from Water Using MgO Nanoparticles Synthesized via DMF-NH₄⁺ Co-Precipitation

by José Antonio Pérez-Tavares, Rocio Casado-Guerrero, Daniel Ramírez-de-Alba, Efrén González-Aguiñaga, Pablo Eduardo Cardoso-Avila, Quetzalcoatl Enrique Saavedra-Arroyo and Rita Patakfalvi

Inorganics 2025, 13(11), 370; https://doi.org/10.3390/inorganics13110370 - 4 Nov 2025

Viewed by 588

Abstract

Fluoride contamination in groundwater is a pressing environmental and public health issue, with chronic exposure linked to skeletal and dental fluorosis. Here, we report the synthesis of magnesium oxide nanoparticles via a controlled co-precipitation method employing dimethylformamide (DMF) as solvent and either ammonium [...] Read more.

Fluoride contamination in groundwater is a pressing environmental and public health issue, with chronic exposure linked to skeletal and dental fluorosis. Here, we report the synthesis of magnesium oxide nanoparticles via a controlled co-precipitation method employing dimethylformamide (DMF) as solvent and either ammonium hydroxide (MgO-1) or ammonium carbonate (MgO-2) as precipitating agents. The resulting materials were comprehensively characterized using thermogravimetric analysis (TGA/DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). Additionally, BET surface area and porosity analyses revealed mesoporous structures, with MgO-1 showing a slightly higher surface area (14.12 m² g⁻¹) than MgO-2 (13.87 m² g⁻¹). Both MgO-1 and MgO-2 exhibited high crystallinity, nanoscale particle sizes (81.6 nm and 128.1 nm, respectively), and distinct morphological features. Batch adsorption studies revealed maximum fluoride uptake capacities of 117.6 mg/g (MgO-1) and 94.5 mg/g (MgO-2) at neutral pH, with MgO-1 exhibiting superior performance due to its smaller particle size and higher specific surface area. Fluoride removal remained above 98% between pH 3–9, confirming stability across a wide pH range, with a minor decline at pH 11 due to OH⁻ competition. Adsorption equilibrium data were best described by the Temkin isotherm model, suggesting heterogeneous surface interactions and an exothermic process, while kinetic analyses indicated pseudo-second-order behavior for MgO-1 and pseudo-first-order for MgO-2. Both materials maintained high fluoride selectivity in the presence of competing anions and successfully reduced fluoride in tap water from 2.11 mg/L to below the WHO limits without altering water hardness. These findings underscore the potential of engineered MgO nanomaterials as efficient, selective, and sustainable adsorbents for water defluoridation, offering a promising pathway toward scalable remediation technologies in fluoride-affected regions. Full article

(This article belongs to the Special Issue Advances in Metal Ion Research and Applications)

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16 pages, 2189 KB

Open AccessArticle

Deep Removal of Fluoride Ions from Spent Ternary Lithium-Ion Batteries Leachate Using Porous La@Zr Adsorbent

by Zaoming Chen, Fupeng Liu, Bin Liao, Tao Zhang, Feixiong Chen, Jie Wang, Chunfa Liao and Shengming Xu

Inorganics 2025, 13(11), 369; https://doi.org/10.3390/inorganics13110369 - 3 Nov 2025

Viewed by 557

Abstract

Hydrometallurgy is currently the mainstream industrial process for recovering valuable components (nickel, cobalt, manganese, lithium, etc.) from spent ternary lithium-ion battery cathode materials. During the crushing of lithium batteries, cathode materials, anode materials (graphite), and electrolytes become mixed. Consequently, fluoride ions inevitably enter [...] Read more.

Hydrometallurgy is currently the mainstream industrial process for recovering valuable components (nickel, cobalt, manganese, lithium, etc.) from spent ternary lithium-ion battery cathode materials. During the crushing of lithium batteries, cathode materials, anode materials (graphite), and electrolytes become mixed. Consequently, fluoride ions inevitably enter the leaching solution during the hydrometallurgical recycling process, with concentrations as high as 100–300 mg/L. These fluoride ions not only adversely affect the quality of the recovered precursor products but also pose environmental risks. To address this issue, this study employs a synthesized lanthanum–zirconium (La@Zr) composite material, with a specific surface area of 67.41 m²/g and a pore size of 2–50 nm, which can reduce the fluoride ion concentration in the leaching solution to below 5 mg/L, significantly lower than the 20 mg/L or higher that is typically achieved with traditional calcium salt defluorination processes, without introducing new impurities. Under optimal adsorption conditions, the lanthanum–zirconium adsorbent exhibits a fluoride ion adsorption capacity of 193.4 mg/g in the leaching solution, surpassing that of many existing metal-based adsorbents. At the same time as the valuable metals, Li, Ni, and Co, are basically not adsorbed, the selective adsorption of fluoride ions can be achieved. Adsorption isotherm studies indicate that the adsorption process follows the Langmuir model, suggesting monolayer adsorption. The secondary adsorption process is primarily governed by chemical adsorption, and elevated temperatures facilitate the removal of fluoride ions. Kinetic studies demonstrate that the adsorption process is well described by the pseudo-second-order model. After desorption and regeneration with NaOH solution, the adsorbent still has a favorable fluoride removal performance, and the adsorption rate of fluoride ions can still reach 95% after four cycles of use. With its high capacity, rapid kinetics, and excellent selectivity, the adsorbent is highly promising for large-scale implementation. Full article

(This article belongs to the Special Issue Novel Materials in Li–Ion Batteries, 2nd Edition)

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20 pages, 1754 KB

Open AccessArticle

Synthesis and Biological Evaluation of Novel Mixed-Ligand ^99mTc-Labeled Anthraquinone Complexes as Potential DNA-Targeted Imaging Agents

by Theofanis Matthaios Migkos, Pigi Glykofridi, Georgios Paparidis, George Psomas, Ioannis S. Vizirianakis, Catherine Gabriel, Dimosthenis Sarigiannis, Ioannis Iakovou and Dionysia Papagiannopoulou

Inorganics 2025, 13(11), 368; https://doi.org/10.3390/inorganics13110368 - 3 Nov 2025

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Abstract

Anthraquinones are molecules with numerous biological properties that can act as DNA intercalators and topoisomerase IIa inhibitors. In this work, the development of technetium-99m radiotracers was pursued via the technetium-tricarbonyl “2 + 1” mixed-ligand approach, fac-[^99mTc][Tc^I(CO)₃(NN′)(N)] [...] Read more.

Anthraquinones are molecules with numerous biological properties that can act as DNA intercalators and topoisomerase IIa inhibitors. In this work, the development of technetium-99m radiotracers was pursued via the technetium-tricarbonyl “2 + 1” mixed-ligand approach, fac-[^99mTc][Tc^I(CO)₃(NN′)(N)]⁺, with a (N,N′) bidentate chelator and a N co-ligand. In one approach, the ligands used were 2,2′-bipyridine (bpy) and N-functionalized-imidazole, where imidazole was conjugated to an anthraquinone moiety. In the other approach, 2-picolylamine and imidazole were used as the mixed-ligand system, where picolylamine was conjugated to an anthraquinone moiety. The synthesis of the ligands was achieved by reaction of 2-picolylamine with a suitably functionalized anthraquinone (Aqpa) or anthrapyrazole (Appa) and imidazole with a suitably functionalized anthraquinone (Aqim). The rhenium reference compounds, fac-[Re^I(CO)₃(bpy)(Aqim)]⁺ with bpy as a bidentate chelator and fac-[Re^I(CO)₃(Aqpa or Appa)(Im)]⁺, with imidazole (Im) as a co-ligand, were synthesized and characterized with spectroscopic methods. The radiotracer technetium-99m complexes fac-[^99mTc][Tc(CO)₃(bpy)(Aqim)]⁺ and fac-[^99mTc][Tc(CO)₃(Aqpa or Appa)(Im)]⁺ were prepared and characterized with standard methods. The purified radiotracers displayed high stability (≥90%) after incubation 24 h in 1 mM L-histidine or rat plasma. The tracers’ cell uptake was evaluated in vitro in CT-26 cells, and their pharmacokinetic properties and tumor uptake were evaluated in vivo in CT26-tumor-bearing mice. The “2 + 1” technetium-tricarbonyl approach leads to in vitro stable tracers, and this mixed-ligand system shows promise for further evaluation. Full article

(This article belongs to the Special Issue Rational Design of Pharmacologically Active Metal-Based Compounds, 2nd Edition)

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31 pages, 5596 KB

Open AccessArticle

Fly Ash as a Secondary Raw Material Improving the Sustainable Characteristics of a Conventional Silicoaluminate Refractory Castable

by Jesús Fernando López-Perales, Leonel Díaz-Tato, Sinuhe Uriel Costilla-Aguilar, Yadira González-Carranza, José Eulalio Contreras de León and Edén Amaral Rodríguez-Castellanos

Inorganics 2025, 13(11), 367; https://doi.org/10.3390/inorganics13110367 - 2 Nov 2025

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Abstract

The global reliance on coal-fired power generation continues to produce vast quantities of fly ash, exceeding 500 million tons annually, with limited recycling rates. Given its high silica (SiO₂) and alumina (Al₂O₃) contents, fly ash represents a [...] Read more.

The global reliance on coal-fired power generation continues to produce vast quantities of fly ash, exceeding 500 million tons annually, with limited recycling rates. Given its high silica (SiO₂) and alumina (Al₂O₃) contents, fly ash represents a promising alternative raw material for sustainable refractory production. In this study, four aluminosilicate refractory castables were formulated using bauxite, calcined flint clay, kyanite, calcium aluminate cement, and microsilica, in which the fine fraction of flint clay was partially replaced by 0, 5, 10, and 15 wt.% fly ash. The specimens were dried at 120 °C and sintered at 850, 1050, and 1400 °C for 4 h. Their physical and mechanical properties were systematically evaluated, while phase evolution and microstructural development were analyzed through X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results revealed that the incorporation of 10 wt.% fly ash (10FAC) provided the optimal balance between densification and strength, achieving compressive strengths of 45.0 MPa and 65.3 MPa after sintering at 1050 °C and 1400 °C, respectively. This improvement is attributed to the formation of a SiO₂-rich liquid phase derived from fly ash impurities, which promoted the in-situ crystallization of acicular secondary mullite and enhanced interparticle bonding among corundum grains. The 10FAC castable also exhibited only a slight increase in apparent porosity (26.39%) compared with the reference (25.74%), indicating effective sintering without excessive vitrification. Overall, the study demonstrates the technical viability of using fly ash as a sustainable substitute for flint clay in refractory castables. The findings contribute to advancing circular economy principles by promoting industrial waste valorization and resource conservation, offering a low-carbon pathway for the development of high-performance refractory materials for structural and thermal applications in energy-intensive industries. Full article

(This article belongs to the Special Issue Recent Advances in Sustainable Ceramic Matrix Composites)

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14 pages, 6514 KB

Open AccessArticle

The Effect of Different Sintering Protocols on the Mechanical and Microstructural Properties of Two Multilayered Zirconia Ceramics: An In Vitro Study

by Lana Alatrash and Asude Dilek Nalbant

Inorganics 2025, 13(11), 366; https://doi.org/10.3390/inorganics13110366 - 1 Nov 2025

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Abstract

This study evaluated the effects of different sintering protocols on the mechanical and microstructural properties of two multilayered zirconia materials: strength-gradient zirconia (KATANA YML) and color-gradient zirconia (KATANA UTML). Bar-shaped specimens were fabricated from both zirconia types. Three sintering protocols were applied: a [...] Read more.

This study evaluated the effects of different sintering protocols on the mechanical and microstructural properties of two multilayered zirconia materials: strength-gradient zirconia (KATANA YML) and color-gradient zirconia (KATANA UTML). Bar-shaped specimens were fabricated from both zirconia types. Three sintering protocols were applied: a manufacturer-recommended conventional protocol (7 h at 1550 °C), a high-speed protocol (54 min at 1600 °C), and a modified high-speed protocol (51 min at 1600 °C). Eighty-four specimens underwent three-point flexural strength testing. SEM and XRD analyses were used to assess microstructure and phase composition. No significant differences in flexural strength were found among sintering protocols (p > 0.05), but YML consistently showed higher strength than UTML (p < 0.05). The highest strength in YML was observed after high-speed sintering, followed by the shortened and conventional protocols. In UTML, the modified protocol yielded the highest strength, followed by the high-speed and then conventional protocol. SEM revealed finer, more homogeneous grains with shorter sintering times. XRD confirmed stable phase composition across all protocols. High-speed and modified high-speed sintering protocols can reduce processing time without compromising zirconia’s mechanical performance. Material type had a greater effect on flexural strength than sintering time, though microstructure was protocol dependent. Proper selection of zirconia type and sintering strategy is essential for optimal outcomes. Full article

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22 pages, 4491 KB

Open AccessArticle

Methacrylic Photopolymerizable Resin Incorporating Selenium Nanoparticles as a Basis for Additive Manufacturing of Functional Materials with Unique Biological Properties

by Dmitriy E. Burmistrov, Ilya V. Baimler, Fatikh M. Yanbaev, Maxim E. Astashev, Valeriy A. Kozlov, Dmitry A. Serov, Aleksandr V. Simakin and Sergey V. Gudkov

Inorganics 2025, 13(11), 365; https://doi.org/10.3390/inorganics13110365 - 1 Nov 2025

Viewed by 548

Abstract

Despite the widespread use of photopolymerizable methacrylate resins in additive manufacturing, their potential for creating functional biomedical materials remains untapped. Standard resins, while possessing good technological properties, are typically biologically inert and unable to combat such a critical problem as bacterial colonization. In [...] Read more.

Despite the widespread use of photopolymerizable methacrylate resins in additive manufacturing, their potential for creating functional biomedical materials remains untapped. Standard resins, while possessing good technological properties, are typically biologically inert and unable to combat such a critical problem as bacterial colonization. In this work, we propose incorporating selenium nanoparticles (Se NPs) into a photopolymerizable resin based on methacrylate monomers to obtain functional composite materials in the MSLA printing process. Composite material samples made from modified resins showed no structural surface defects and were characterized by a non-uniform distribution of NPs in volume and demonstrated a higher degree of monomer conversion. The materials demonstrated significant antioxidant activity, removing OH-radicals and H₂O₂ and reducing the level of biomarkers of oxidative damage (8-oxoguanine in DNA and long-lived reactive protein species). A dose-dependent bacteriostatic effect was observed in E. coli cell cultures against a background of high cytocompatibility with human cell cultures. The developed photopolymerizable resins modified with Se NPs allow obtaining products that combine the properties of a bacteriostatic agent with antioxidant properties and high biocompatibility, which is of considerable interest in terms of materials for biomedical applications. Full article

(This article belongs to the Special Issue Advances in Metallic Nanoparticles for Antibacterial and Antibiofilm Control)

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35 pages, 4540 KB

Open AccessReview

Recent Progress of β-Ga₂O₃ Power Diodes: A Comprehensive Review

by Lin-Qing Zhang, Jia-Jia Liu, Ya-Ting Tian, Han Xi, Qing-Hua Yue, Hong-Fang Li, Zhi-Yan Wu and Li-Fang Sun

Inorganics 2025, 13(11), 364; https://doi.org/10.3390/inorganics13110364 - 31 Oct 2025

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Abstract

Ultra-bandgap semiconductor material, β-gallium oxide (β-Ga₂O₃), has great potential for fabricating the next generation of high-temperature, high-voltage power devices due to its superior material properties and cost competitiveness. In addition, β-Ga₂O₃ has the advantages of high-quality, [...] Read more.

Ultra-bandgap semiconductor material, β-gallium oxide (β-Ga₂O₃), has great potential for fabricating the next generation of high-temperature, high-voltage power devices due to its superior material properties and cost competitiveness. In addition, β-Ga₂O₃ has the advantages of high-quality, large-size, low-cost, and controllable doping, which can be realized by the melt method. It has a wide bandgap of 4.7–4.9 eV, a large breakdown field strength of 8 MV/cm, and a Baliga figure of merit (BFOM) as high as 3000, which is approximately 10 and 4 times that of SiC and GaN, respectively. These properties enable β-Ga₂O₃ to be strongly competitive in power diodes and metal-oxide-semiconductor field-effect transistor (MOSFET) applications. Most of the current research is focused on electrical characteristics of those devices, including breakdown voltage (V_BR), specific on-resistance (R_ON,SP), power figure of merit (PFOM), etc. Considering the rapid development of β-Ga₂O₃ diode technology, this review mainly introduces the research progress of different structures of β-Ga₂O₃ power diodes, including vertical and lateral structures with various advanced techniques. A detailed analysis of Ga₂O₃-based high-voltage power diodes is presented. This review will help our theoretical understanding of β-Ga₂O₃ power diodes as well as the development trends of β-Ga₂O₃ power application schemes. Full article

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11 pages, 1821 KB

Open AccessArticle

High-Frequency Modulation Characteristics Based on HfZrO Ferroelectric

by Junxiu Zhou, Zeyang Xiang, Kexiang Wang, Jie Lu, Haoyu Li, Yun Wen, Junyu Wang, Xinyu Cao, Weitian Xu, Yu Meng and Ran Jiang

Inorganics 2025, 13(11), 363; https://doi.org/10.3390/inorganics13110363 - 31 Oct 2025

Viewed by 719

Abstract

This work investigates the application of HfZrO ferroelectric material for the tuning of high-frequency bandpass filters. By integrating HfZrO with a two-dimensional HfSe semiconductor to form a heterostructure, the device achieves wideband tunability with low power requirements. Under a bias of ±4 V, [...] Read more.

This work investigates the application of HfZrO ferroelectric material for the tuning of high-frequency bandpass filters. By integrating HfZrO with a two-dimensional HfSe semiconductor to form a heterostructure, the device achieves wideband tunability with low power requirements. Under a bias of ±4 V, the bandpass filter demonstrates a 3.4 GHz tuning range—from 7.8 GHz to 11.2 GHz—corresponding to a fractional tunability of approximately 43% in the X-band. The insertion loss remains below −1.8 dB across the tuning window, indicating low-loss operation. These results highlight the potential of the HfZrO/HfSe heterostructure as a promising platform for energy-efficient, CMOS-compatible, high-frequency tunable devices. Full article

(This article belongs to the Special Issue Recent Research and Application of Amorphous Materials, 2nd Edition)

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18 pages, 2299 KB

Open AccessArticle

Mechanistic Aspects of the Photofunctionalisation of Tetraalkylammonium Cations by [PtCl₆]²⁻

by Imelda H. Silalahi, Marsel Z. Shafikov, Ananya Sen, Philip Groves, Adrian C. Whitwood, Victor Chechik, Caroline E. H. Dessent and Duncan W. Bruce

Inorganics 2025, 13(11), 362; https://doi.org/10.3390/inorganics13110362 - 30 Oct 2025

Viewed by 451

Abstract

Unexpected activation of the tetrabutylammonium cation in the presence of hexachloroplatinate(IV) under light to give a dinuclear complex of trans-μ²:η²,η²-1,3-butadiene-bis(trichloroplatinate(II)) along with a proposed mechanism of the activation has been reported. The mechanism has been investigated using [...] Read more.

Unexpected activation of the tetrabutylammonium cation in the presence of hexachloroplatinate(IV) under light to give a dinuclear complex of trans-μ²:η²,η²-1,3-butadiene-bis(trichloroplatinate(II)) along with a proposed mechanism of the activation has been reported. The mechanism has been investigated using a combination of photodissociation photodetachment mass spectrometry, and frozen-matrix EPR spectroscopy, in addition to 1D and 2D NMR spectroscopy. In addition to the Bu₄N⁺ salts of [PtCl₆]²⁻ that were part of the original observations, the reactivity of Bu₄P⁺, Pr₄N⁺, and Pe₄N⁺ (Pe = pentyl) salts has also been investigated, and, in addition, the possible involvement of η²-butene complex intermediates has been investigated. The combined results provide additional evidence and support for the originally proposed mechanism of activation of the Bu₄N⁺ cation. Full article

(This article belongs to the Section Organometallic Chemistry)

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17 pages, 2812 KB

Open AccessArticle

Green Manufacturing of Rutile (TiO₂) Welding Electrodes with Blast Furnace Slag

by Mustafa Kaptanoglu

Inorganics 2025, 13(11), 361; https://doi.org/10.3390/inorganics13110361 - 29 Oct 2025

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Abstract

This study develops a sustainable welding approach by incorporating 35–50% blast furnace slag (BFS), a byproduct of the steel industry, into rutile-type electrode coatings. To fabricate the electrodes, BFS was dry-mixed with fluxes, followed by the addition of potassium silicate binder to create [...] Read more.

This study develops a sustainable welding approach by incorporating 35–50% blast furnace slag (BFS), a byproduct of the steel industry, into rutile-type electrode coatings. To fabricate the electrodes, BFS was dry-mixed with fluxes, followed by the addition of potassium silicate binder to create a paste. This mixture was then pressed onto 3.25 mm core wires at 150 bar and heat-treated at 150 °C for two hours. Weld quality and performance were evaluated through visual inspections, microstructure and XRD analyses, hardness, tensile, and impact tests. Visual inspections confirmed weld quality comparable to commercial standards, with stable arc and minimal spatter. Microstructure analysis revealed a ferrite-dominated weld metal with TiO₂ and FeTiO₃ phases in the slag layer, enhancing strength and toughness. Electrodes with 35–40% BFS achieved yield strength of 477–482 MPa, tensile strength of 570–573 MPa, and impact energy of 58–59 J at 0 °C, complying with ISO 2560:2020. BFS integration reduced CO₂ emissions by 0.28–0.4 kg per kg of coating and diverted 200–600 kg of slag per ton of steel from landfills. Coating and raw material costs decreased by 33–48% and 15–25%, respectively, aligning with the EU Green Deal’s circular economy goals and enhancing weld quality and sustainability. Full article

(This article belongs to the Section Inorganic Materials)

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18 pages, 4965 KB

Open AccessArticle

A Theoretical Comparison on Pd-Doped MoSe₂, WSe₂, and MoSe₂-WSe₂ for Adsorption and Sensing of Dissolved Gases (H₂, C₂H₂, and C₂H₄) in Transformer Oil

by Xinyu Guo, Shouxiao Ma and Hao Cui

Inorganics 2025, 13(11), 360; https://doi.org/10.3390/inorganics13110360 - 28 Oct 2025

Cited by 1 | Viewed by 441

Abstract

This study presents a comprehensive first-principles investigation into the gas adsorption and sensing characteristics of Pd-doped MoSe₂, WSe₂, and MoSe₂-WSe₂ systems for dissolved gas analysis applications in oil-filled transformers. Through theoretical simulations, we first establish and [...] Read more.

This study presents a comprehensive first-principles investigation into the gas adsorption and sensing characteristics of Pd-doped MoSe₂, WSe₂, and MoSe₂-WSe₂ systems for dissolved gas analysis applications in oil-filled transformers. Through theoretical simulations, we first establish and characterize three distinct Pd-doped systems, examining their structural stability, electronic properties, and gas interaction mechanisms with key typical gases (H₂, C₂H₂, and C₂H₄). Our analysis reveals that the Pd@MoSe₂-WSe₂ heterojunction exhibits exceptional sensing performance, with calculated response values of −77.67% (H₂), −95.98% (C₂H₂), and −96.88% (C₂H₄)—significantly surpassing the capabilities of both Pd-MoSe₂ and Pd-WSe₂ monolayers. The observed response hierarchy (C₂H₄ > C₂H₂ > H₂) correlates directly with the degree of adsorption energy, charge transfer, and bandgap modification induced by gas adsorption. Finally, the reason for such enhancements are systemically analyzed. The findings not only position Pd@MoSe₂-WSe₂ as an outstanding candidate for condition evaluation in oil-filled transformers but also establish a structure–property relationship that uncovers the feasibility of a strategic heterojunction design to enhance the adsorption and sensing performances for typical gas species. Full article

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22 pages, 18896 KB

Open AccessArticle

Solvent-Driven Structural Modulation of Co-Ni₃S₂ and Impact on Electrochemical Water Splitting

by Sagar M. Mane, Komal S. Wagh, Sangoh Lee, Aviraj M. Teli, Ganesh T. Chavan, Jae Cheol Shin and Jaewoong Lee

Inorganics 2025, 13(11), 359; https://doi.org/10.3390/inorganics13110359 - 28 Oct 2025

Viewed by 494

Abstract

Understanding the role of synthesis parameters in tailoring catalyst morphology is crucial for enhancing performance in electrochemical water splitting. This research systematically explores how different solvent environments affect the structural evolution and morphology of cobalt-doped nickel sulfide (Co-Ni₃S₂) nanomaterials. [...] Read more.

Understanding the role of synthesis parameters in tailoring catalyst morphology is crucial for enhancing performance in electrochemical water splitting. This research systematically explores how different solvent environments affect the structural evolution and morphology of cobalt-doped nickel sulfide (Co-Ni₃S₂) nanomaterials. By systematically modifying the solvent environment using ethylene glycol and glycerol, distinct morphologies of Co-Ni₃S₂ were obtained, leading to variations in their electrocatalytic water-splitting performance. The fabricated compounds were thoroughly tested for their catalytic performance in facilitating hydrogen and oxygen evolution processes. Notably, the use of ethylene glycol as a synthesis medium led to the formation of a unique interconnected petal-like structure, significantly improving electrocatalytic activity, as evidenced by low overpotentials of 190.7 mV for HER at 10 mA cm⁻² and 414 mV for OER at 30 mA cm⁻². In contrast, when glycerol was employed as the solvent, the resulting Co-Ni₃S₂ material displayed overpotentials of 223.8 mV and 535 mV for HER and OER, respectively. Eventually, Co-doping was found to enhance the electrocatalytic performance, as pure Ni₃S₂ synthesized under the same solvent conditions exhibited higher overpotentials for both HER and OER. These findings underscore the crucial role of solvent selection in tailoring the structural and functional properties of materials for high-performance electrochemical applications. Full article

(This article belongs to the Special Issue Featured Papers in Inorganic Materials 2025)

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12 pages, 2106 KB

Open AccessArticle

Enhanced Phase Stability of Sm₂(Fe, Al)₁₇C_x

by Xubo Liu and Ikenna C. Nlebedim

Inorganics 2025, 13(11), 358; https://doi.org/10.3390/inorganics13110358 - 28 Oct 2025

Viewed by 425

Abstract

Aluminum doping can improve the phase stability of metastable compound Sm₂Fe₁₇C_x with a high carbon content (x > 1.5). We investigated the preferential site substitution of Al, chemical bonding, and structural stability in Sm₂(Fe,Al)₁₇C [...] Read more.

Aluminum doping can improve the phase stability of metastable compound Sm₂Fe₁₇C_x with a high carbon content (x > 1.5). We investigated the preferential site substitution of Al, chemical bonding, and structural stability in Sm₂(Fe,Al)₁₇C₃ using first-principle calculations. Our results reveal a strong correlation between the preferential substitution of Fe by Al and the atomic site chemical environment, which affects the overall phase stability. Specifically, Al preferentially occupies the 9d site in Sm₂(Fe,Al)₁₇C₃. At the same time, Al prefers the site 6c in its parent phase Sm₂(Fe,Al)₁₇. Partial replacement of Fe with Al leads to a more negative formation energy, indicating enhanced thermodynamic stability. Crystal Orbital Hamilton Population (COHP) and Crystal Orbital Bond Index (COBI) analysis suggest that insertion of carbon weakens the bonding strength of Sm-Fe (18f) and Sm-Fe (18h), resulting in metastability of Sm₂Fe₁₇C_x. Doping Al strengthens Al-Fe, Al-Sm, Sm-Fe (18f, 18h) and Fe–C bonding in Sm₂(Fe,Al)₁₇C₃, as revealed by calculated COHP and COBI. These effects contribute to improved phase stability in the Al-doped 2:17 interstitial compound. Full article

(This article belongs to the Section Inorganic Materials)

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21 pages, 2996 KB

Open AccessArticle

Two Mechanism Pathways from a Versatile Arene Ruthenium Assembly: Reaching Aqueous Sensing Reversibility and Selectivity for CN⁻

by Alaa Maatouk, Thibaud Rossel, Gioele Colombo, Stefano Brenna and Bruno Therrien

Inorganics 2025, 13(11), 357; https://doi.org/10.3390/inorganics13110357 - 28 Oct 2025

Viewed by 569

Abstract

The development of highly selective, sensitive and recyclable chemosensors for CN⁻ is critical due to the widespread use of cyanide derivatives in industrial processes and its extreme toxicity to environmental and biological systems. Herein, we report the synthesis and characterization of a [...] Read more.

The development of highly selective, sensitive and recyclable chemosensors for CN⁻ is critical due to the widespread use of cyanide derivatives in industrial processes and its extreme toxicity to environmental and biological systems. Herein, we report the synthesis and characterization of a water-soluble arene ruthenium metalla-assembly specifically designed to operate in aqueous solutions and under environmentally relevant conditions. The arene ruthenium assembly incorporates functionalized building blocks that enable a selective multi-site recognition of cyanide according to pH by either nucleophilic addition or hydrogen bond interactions. The system exhibits a distinct colorimetric response upon cyanide binding, resulting in a rapid “turn-on” color change. An excellent selectivity and reversibility for cyanide recognition is observed over multiple cycles, with a detection limit in the low micromolar range, thus laying the ground for the future development of sensing technology with supramolecular metal-based assemblies. Full article

(This article belongs to the Special Issue Application of Transition Metal Complexes in Biomedical and Chemical Fields)

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15 pages, 2796 KB

Open AccessArticle

The Effect of Nb Doping on the Thermoelectric Properties of Indium Oxide

by Tongqiang Xiong, Bo Feng, Haitao Zhang, Wenzheng Li, Tong Tang, Ruolin Ruan, Peng Jin, Guopeng Zhou and Heng Zhao

Inorganics 2025, 13(11), 356; https://doi.org/10.3390/inorganics13110356 - 28 Oct 2025

Viewed by 471

Abstract

To optimize the performance of indium oxide (In₂O₃)-based thermoelectric materials, this study prepared Nb-doped In₂O₃ via mechanical alloying and spark plasma sintering (SPS), investigating its regulatory mechanism on the crystal structure, as well as on thermoelectric [...] Read more.

To optimize the performance of indium oxide (In₂O₃)-based thermoelectric materials, this study prepared Nb-doped In₂O₃ via mechanical alloying and spark plasma sintering (SPS), investigating its regulatory mechanism on the crystal structure, as well as on thermoelectric and mechanical properties. X-ray diffraction (XRD) showed that Nb was incorporated into the In₂O₃ lattice; with increasing Nb doping, the lattice constant decreased due to the ionic radius difference between Nb (64 pm) and In³⁺ (80 pm) plus Nb’s strong polarization effect. In electrical properties, Nb doping significantly improved conductivity: pure In₂O₃ had ~53.42 S/cm, reaching 272.07 S/cm (over 5x increase) at x = 0.005, which is attributed to Nb releasing free electrons and increasing the carrier concentration; though carrier mobility slightly decreased, carrier concentration growth dominated conductivity improvement. The absolute Seebeck coefficient decreased (from −185.24 μV/K to −120.12 μV/K at x = 0.005), but electrical conductivity increased and far exceeded the decrease in the square of the Seebeck coefficient, leading to a high-temperature power factor of 5.10 μW/(cm·K²). In terms of thermal properties, Nb doping reduced thermal conductivity and lattice thermal conductivity. Collectively, the x = 0.004 sample achieved a ZT value of 0.302 at 800 K, which is over 5 times higher than that of pure In₂O₃ (0.055 at 973 K); meanwhile, Nb doping enhanced the Vickers hardness, realizing the optimization of thermoelectric and mechanical properties. Full article

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19 pages, 8169 KB

Open AccessArticle

The Electrochemical Performance of Co₃O₄ Electrodes with Platinum Nanoparticles for Chlorine Evolution

by Guan-Ting Pan and Aleksandar N. Nikoloski

Inorganics 2025, 13(11), 355; https://doi.org/10.3390/inorganics13110355 - 28 Oct 2025

Viewed by 546

Abstract

Different morphologies of cobalt oxide (Co₃O₄) electrodes were prepared through the electrochemical deposition technique with various electrodeposition times from 10 min to 50 min. Platinum (Pt) nanoparticles were deposited on the Co₃O₄ electrodes through sputter coating. [...] Read more.

Different morphologies of cobalt oxide (Co₃O₄) electrodes were prepared through the electrochemical deposition technique with various electrodeposition times from 10 min to 50 min. Platinum (Pt) nanoparticles were deposited on the Co₃O₄ electrodes through sputter coating. The crystallographic, microstructural, surface functional, textural–structural, and electric properties of the Co₃O₄ electrodes were investigated. X-ray diffraction analysis identified a pure cubic Co₃O₄ crystal structure in the samples. In the electrodeposition process, the microstructure of the electrodes varied from hierarchical 3D flower-like to 2D hexagonal porous nanoplates due to an increase in oxygen vacancies. The carrier densities of all samples were between 5.77 × 10¹⁴ cm⁻³ and 8.77 × 10¹⁴ cm⁻³. The flat band potentials of all samples were between −5.91 V and −6.21 V vs. an absolute electron potential, and the potential values for electrodes became more positive as the oxygen vacancy concentration in the film structure increased. The 2D hexagonal porous nanoplate Pt/Co₃O₄ electrodes offered the highest oxygen vacancies and thus the maximum current density of 102.66 mA/cm², with an external potential set at 1.5 V vs. an Ag/AgCl reference electrode. Full article

(This article belongs to the Special Issue Advanced Inorganic Nanomaterials for Energy Conversion and Catalysis Applications, 2nd Edition)

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31 pages, 15662 KB

Open AccessReview

Prussian Blue Analogues and Their Derivatives for the Oxygen Evolution Reaction: A Review on Active Site Engineering Strategies

by Zhen Cao, Haozhe Shi, Tingting Zhou, Wenhui Yan, Jiahong Song, Pengqi Feng, Kaili Wang and Zaiyong Jiang

Inorganics 2025, 13(11), 354; https://doi.org/10.3390/inorganics13110354 - 28 Oct 2025

Viewed by 1291

Abstract

The oxygen evolution reaction (OER) is a kinetic bottleneck in electrochemical water splitting, creating an urgent need for the development of efficient electrocatalysts. Prussian blue analogues (PBAs), a significant class of inorganic coordination polymers, have emerged as excellent precursors and pre-catalysts for preparing [...] Read more.

The oxygen evolution reaction (OER) is a kinetic bottleneck in electrochemical water splitting, creating an urgent need for the development of efficient electrocatalysts. Prussian blue analogues (PBAs), a significant class of inorganic coordination polymers, have emerged as excellent precursors and pre-catalysts for preparing various OER nanocatalysts, owing to their numerous advantages such as tunable composition, controllable morphology, and structural derivability. This review systematically summarizes recent advances in PBA-based OER electrocatalysts, beginning with two core strategies: enhancing active site accessibility and utilization, and improving the intrinsic activity of each active site. We provide an in-depth discussion of the design principles for enhancing active site accessibility and utilization through constructing porous architectures, creating hierarchical porosity, and improving electrical conductivity. The review also details key approaches for improving intrinsic activity, including regulating electronic structure via elemental doping and optimizing active sites via defect engineering, while examining the underlying mechanisms for performance enhancement. Finally, current challenges and future research directions are outlined, offering a perspective on the potential applications of PBA-based catalysts in sustainable energy conversion systems. Full article

(This article belongs to the Special Issue Advanced Inorganic Nanomaterials for Energy Conversion and Catalysis Applications, 2nd Edition)

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17 pages, 1113 KB

Open AccessReview

Towards Sustainable Processing of Chromite Resources: A Review of Methods for Magnesium and Platinum-Group Metal Extraction

by Rinat Abdulvaliyev, Yerkezhan Abikak, Nazym Akhmadiyeva, Sergey Gladyshev, Alfiyam Manapova and Asiya Kasymzhanova

Inorganics 2025, 13(11), 353; https://doi.org/10.3390/inorganics13110353 - 27 Oct 2025

Viewed by 642

Abstract

This article provides a review of modern technologies for processing chromite ores and beneficiation wastes, with a focus on the recovery of magnesium and platinum-group metals (PGMs). It reveals that the traditional use of chromites solely as a source of chromium limits the [...] Read more.

This article provides a review of modern technologies for processing chromite ores and beneficiation wastes, with a focus on the recovery of magnesium and platinum-group metals (PGMs). It reveals that the traditional use of chromites solely as a source of chromium limits the potential of this raw material, whereas comprehensive processing enables the recovery of associated components, including serpentine minerals, which are widely present in chromite ores and tailings. Pyrometallurgical, hydrometallurgical, plasma-arc, and biotechnological methods are examined, as well as their integration into combined flowsheets. Particular attention is given to sulfation, chloridization, and carbochlorination processes, which ensure a high degree of PGM recovery. Economic and environmental aspects of comprehensive processing are discussed, including carbon footprint reduction, waste minimization, and prospects for the development of “green metallurgy.” It is concluded that the further advancement of resource-efficient and environmentally safe technologies for chromite processing will increase production efficiency, ensure resource independence, and support compliance with global carbon neutrality requirements. Full article

(This article belongs to the Special Issue Mixed Metal Oxides, 3rd Edition)

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21 pages, 3052 KB

Open AccessReview

Chiral Hybrid Organic–Inorganic Metal Halides: Preparation, Luminescent Properties, and Applications

by Hui Zhu, Zhenwen Sheng, Bo Shao, Yu He, Zhuang Liu, Suqin Wang and Zhi Sheng

Inorganics 2025, 13(11), 352; https://doi.org/10.3390/inorganics13110352 - 27 Oct 2025

Viewed by 669

Abstract

Organic–inorganic metal halides (OIMHs) have emerged as highly promising semiconductor materials owing to their outstanding optoelectronic properties. Incorporation of chiral organic molecules into the metal–halide framework enables the construction of chiral OIMHs, which exhibit unique chiroptical phenomena in addition to the intrinsic advantages [...] Read more.

Organic–inorganic metal halides (OIMHs) have emerged as highly promising semiconductor materials owing to their outstanding optoelectronic properties. Incorporation of chiral organic molecules into the metal–halide framework enables the construction of chiral OIMHs, which exhibit unique chiroptical phenomena in addition to the intrinsic advantages of perovskite-based semiconductors. This review provides a systematic overview of recent progress in chiral OIMHs, covering synthetic approaches, crystal structures, mechanisms of chirality transfer, circularly polarized luminescence, and circularly polarized light detection. We further highlight the current challenges and outline future research directions, emphasizing the need for strategies that enhance chiroptical responses, stability, and device integration. By bridging fundamental insights with design principles, this work aims to guide the rational development of next-generation chiral functional materials for advanced optoelectronic and spintronic applications. Full article

(This article belongs to the Special Issue Advanced Inorganic Semiconductor Materials, 3rd Edition)

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27 pages, 4601 KB

Open AccessReview

Recent Progress of Plasmonic Perovskite Photodetectors

by Hongki Kim, Jeongeun Lee, Chae Bin Lee and Yoon Ho Lee

Inorganics 2025, 13(11), 351; https://doi.org/10.3390/inorganics13110351 - 27 Oct 2025

Viewed by 926

Abstract

Perovskite materials have emerged as promising candidates for next-generation photodetectors (PDs) owing to their superior optoelectronic properties and compatibility with low-cost, low-temperature fabrication processes. Broad applicability of PDs spans diverse fields, including X-ray detection, wearable electronics, autonomous vehicles, artificial intelligence, imaging, optical communication, [...] Read more.

Perovskite materials have emerged as promising candidates for next-generation photodetectors (PDs) owing to their superior optoelectronic properties and compatibility with low-cost, low-temperature fabrication processes. Broad applicability of PDs spans diverse fields, including X-ray detection, wearable electronics, autonomous vehicles, artificial intelligence, imaging, optical communication, and biomedical sensing, offering advantages over conventional semiconductor PDs based on Si, Ge, InGaAs, and GaN. The integration of plasmonic nanostructures into perovskite-based devices has recently emerged as an effective strategy to enhance performance by amplifying light absorption near the perovskite layer. This review summarizes recent advances and design strategies for plasmonic-integrated perovskite photodetectors (Pe-PDs), with a particular emphasis on plasmonic nanopatterns and nanoparticles as viable approaches for solution-processable Pe-PDs. Full article

(This article belongs to the Special Issue Recent Progress in Perovskites)

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16 pages, 36018 KB

Open AccessArticle

Ultra-Rapid Synthesis of Co₃O₄ Nanostructures with Tunable Morphology via Nickel-Assisted Anodization

by Leydi Julieta Cardenas Flechas, Jorge Bautista-Ruiz, Paulo Tarso Cavalcante Freire, Elaine Cristina Paris and Miryam Rincón Joya

Inorganics 2025, 13(11), 350; https://doi.org/10.3390/inorganics13110350 - 26 Oct 2025

Cited by 1 | Viewed by 469

Abstract

Various morphologies of cobalt oxide Co₃O₄ films on cobalt (Co) foils were obtained via anodization followed by a thermal treatment at 350 °C. This study introduces a rapid and cost-effective synthesis route, achieving well-defined spinel structures in only 30 min. [...] Read more.

Various morphologies of cobalt oxide Co₃O₄ films on cobalt (Co) foils were obtained via anodization followed by a thermal treatment at 350 °C. This study introduces a rapid and cost-effective synthesis route, achieving well-defined spinel structures in only 30 min. The novelty of this work lies in exploring nickel (Ni) as a morphological modifier in the anodization electrolyte. FESEM analysis revealed that, while anodization without Ni produced nanoflake structures, the inclusion of Ni transformed the morphology into larger cubic crystals and rice grain–shaped nanoparticles. XPS confirmed the presence of oxygen vacancies during phase formation, TEM showed spinel grains smaller than 20 nm, and Raman spectroscopy exhibited characteristic peak shifts influenced by both anodization and Ni addition. These results demonstrate that Ni not only accelerates the formation of spinel

C o_{3} O_{4}

but also plays a decisive role in tailoring morphology, highlighting the efficiency and novelty of this approach. Full article

(This article belongs to the Special Issue Feature Papers in Inorganic Solid-State Chemistry 2025)

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19 pages, 17305 KB

Open AccessArticle

Unraveling the Fe-Dependent Phase Evolution and Structure of Ni-Fe/γ-Al₂O₃ Catalysts: A Combined Experimental and Computational Study

by Semyon A. Gulevich, Mariya P. Shcherbakova-Sandu, Eugene P. Meshcheryakov, Yurij A. Abzaev, Sergey A. Guda, Ritunesh Kumar, Akshay K. Sonwane, Sonali Samal, Ajay K. Kushwaha and Irina A. Kurzina

Inorganics 2025, 13(11), 349; https://doi.org/10.3390/inorganics13110349 - 24 Oct 2025

Cited by 1 | Viewed by 492

Abstract

Nickel–iron (Ni-Fe) catalysts are widely used in industry due to their cost-effectiveness and versatile catalytic properties. This work investigates the structural and morphological characteristics of Ni-Fe catalysts supported on γ-Al₂O₃, synthesized with varying Ni/Fe atomic ratios (from 1:1 to [...] Read more.

Nickel–iron (Ni-Fe) catalysts are widely used in industry due to their cost-effectiveness and versatile catalytic properties. This work investigates the structural and morphological characteristics of Ni-Fe catalysts supported on γ-Al₂O₃, synthesized with varying Ni/Fe atomic ratios (from 1:1 to 20:1). The catalysts were characterized using a combination of experimental techniques including X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM/TEM), and selected-area electron diffraction (SAED). Theoretical modeling using the USPEX evolutionary algorithm complemented the experimental data by predicting stable Ni-Fe crystal structures. The results revealed uniform metal distribution on the support with particle sizes ranging from 4.1 to 4.5 nm. SAED analysis confirmed the formation of an intermetallic FeNi phase, particularly in samples with higher iron content. This study demonstrates Ni-Fe interaction effects and will be of interest to researchers in catalysis and materials science working on the development of bimetallic systems. Full article

(This article belongs to the Section Inorganic Materials)

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