Inorganics

13 pages, 4090 KiB

Open AccessArticle

Luminescence Study of Hydrogenated Silicon Oxycarbide (SiO_xC_y:H) Thin Films Deposited by Hot Wire Chemical Vapor Deposition as Active Layers in Light Emitting Devices

by Juan R. Ramos-Serrano, Yasuhiro Matsumoto, Alejandro Ávila, Gabriel Romero, Maricela Meneses, Alfredo Morales, José A. Luna, Javier Flores, Gustavo M. Minquiz and Mario Moreno-Moreno

Inorganics 2024, 12(11), 298; https://doi.org/10.3390/inorganics12110298 - 20 Nov 2024

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Abstract

The obtention of luminescent SiO_xC_y:H thin films deposited by the HW-CVD technique is reported here. We study the effect of different monomethyl-silane (MMS) flow rates on the films properties. An increase in the emission bandwidth and a red-shift was [...] Read more.

The obtention of luminescent SiO_xC_y:H thin films deposited by the HW-CVD technique is reported here. We study the effect of different monomethyl-silane (MMS) flow rates on the films properties. An increase in the emission bandwidth and a red-shift was observed when the MMS flow increased. The luminescence was related to optical transitions in band tail states and with less contribution from quantum confinement effects. After, the films were annealed at 750 °C in nitrogen. The annealed film deposited at the highest MMS flow showed an emission spectrum like the as-deposited film, suggesting the same emission mechanisms. By contrast, the annealed film deposited at the lowest MMS flow showed two emission bands. These bands are due to the activation of radiative defects related to oxygen-deficient centers. MOS-like structures were fabricated as electroluminescent devices using the annealed films. Only the structure of the film with the highest carbon content showed light emission in a broad band in the visible spectrum region in forward bias, with a maximum centered close to 850 nm. The light emission mechanism was related to electron thermalization in the band tail states and a direct hole injection into deep states. The trap-assisted tunneling, Poole–Frenkel emissions and Fowler–Nordheim tunneling were proposed as the charge transport mechanism. Full article

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

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16 pages, 7984 KiB

Open AccessArticle

Efficient Catalytic Reduction of Organic Pollutants Using Nanostructured CuO/TiO₂ Catalysts: Synthesis, Characterization, and Reusability

by Mariyem Abouri, Abdellah Benzaouak, Fatima Zaaboul, Aicha Sifou, Mohammed Dahhou, Mohammed Alaoui El Belghiti, Khalil Azzaoui, Belkheir Hammouti, Larbi Rhazi, Rachid Sabbahi, Mohammed M. Alanazi and Adnane El Hamidi

Inorganics 2024, 12(11), 297; https://doi.org/10.3390/inorganics12110297 - 19 Nov 2024

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Abstract

The catalytic reduction of organic pollutants in water is a critical environmental challenge due to the persistent and hazardous nature of compounds like azo dyes and nitrophenols. In this study, we synthesized nanostructured CuO/TiO₂ catalysts via a combustion technique, followed by calcination [...] Read more.

The catalytic reduction of organic pollutants in water is a critical environmental challenge due to the persistent and hazardous nature of compounds like azo dyes and nitrophenols. In this study, we synthesized nanostructured CuO/TiO₂ catalysts via a combustion technique, followed by calcination at 700 °C to achieve a rutile-phase TiO₂ structure with varying copper loadings (5–40 wt.%). The catalysts were characterized using X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR–FTIR) spectroscopy, thermogravimetric analysis-differential thermal analysis (TGA–DTA), UV-visible diffuse reflectance spectroscopy (DRS), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDS). The XRD results confirmed the presence of the crystalline rutile phase in the CuO/TiO₂ catalysts, with additional peaks indicating successful copper oxide loading onto TiO₂. The FTIR spectra confirmed the presence of all the functional groups in the prepared samples. SEM images revealed irregularly shaped copper oxide and agglomerated TiO₂ particles. The DRS results revealed improved optical properties and a decreased bandgap with increased Cu content, and 4-Nitrophenol (4-NP) and methyl orange (MO), which were chosen for their carcinogenic, mutagenic, and nonbiodegradable properties, were used as model organic pollutants. Catalytic activities were tested by reducing 4-NP and MO with sodium borohydride (NaBH₄) in the presence of a CuO/TiO₂ catalyst. Following the in situ reduction of CuO/TiO₂, Cu (NPs)/TiO₂ was formed, achieving 98% reduction of 4-NP in 480 s and 98% reduction of MO in 420 s. The effects of the NaBH₄ concentration and catalyst mass were investigated. The catalysts exhibited high stability over 10 reuse cycles, maintaining over 96% efficiency for MO and 94% efficiency for 4-NP. These findings demonstrate the potential of nanostructured CuO/TiO₂ catalysts for environmental remediation through efficient catalytic reduction of organic pollutants. Full article

(This article belongs to the Special Issue New Advances into Nanostructured Oxides, 2nd Edition)

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25 pages, 15721 KiB

Open AccessArticle

Studies of Various Batch Adsorption Parameters for the Removal of Trypan Blue Using Ni-Zn-Bi-Layered Triple Hydroxide and Their Isotherm, Kinetics, and Removal Mechanism

by Ganesan Sriram, Nimisha Baby, Karmegam Dhanabalan, Muthuraj Arunpandian, Karuppaiah Selvakumar, Thangarasu Sadhasivam and Tae Hwan Oh

Inorganics 2024, 12(11), 296; https://doi.org/10.3390/inorganics12110296 - 19 Nov 2024

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Abstract

The present study addressed the removal of Trypan blue (TB) from water using a novel Ni-Zn-Bi-layered triple hydroxide (NZB LTH or NZB) synthesized through the co-precipitation technique. The physiochemical properties of NZB were analyzed before and after TB adsorption using XRD, BET, FESEM, [...] Read more.

The present study addressed the removal of Trypan blue (TB) from water using a novel Ni-Zn-Bi-layered triple hydroxide (NZB LTH or NZB) synthesized through the co-precipitation technique. The physiochemical properties of NZB were analyzed before and after TB adsorption using XRD, BET, FESEM, FTIR-ATR, Raman, and XPS. Studies on adsorption indicate that 80 mg of NZB has a maximum TB removal effectiveness of around 96.7% at natural pH (~4.5–5.0). This study found that NZB has a maximum adsorption capacity (q_max) of 5.3 mg·g⁻¹ at dye concentrations ranging from 5 to 30 mg·L⁻¹. When combined with various anionic dye mixtures, NZB’s selectivity studies showed that it is highly selective for the removal of TB and is also effective at removing cationic dyes. When compared to Na₂SO₄ and NaCl salts, NZB had a lower dye removal percentage for TB removal in the presence of Na₂SO₃. In an adsorption process, the interaction between the TB and NZB in an aqueous solution is caused by hydrogen bonding and electrostatic interactions, which are investigated in the adsorption mechanism. In comparison with ethanol and methanol, the recyclability investigation of NZB revealed the notable removal of TB using 0.1 M NaOH for the desorption. Therefore, the present investigation suggests that NZB is an appropriate adsorbent for the removal of TB from an aqueous solution. Full article

(This article belongs to the Special Issue Feature Papers in Inorganic Materials 2024)

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17 pages, 6530 KiB

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Uranium-Mediated Thiourea/Urea Conversion on Chelating Ligands

by Christelle Njiki Noufele, Maximilian Roca Jungfer, Adelheid Hagenbach, Hung Huy Nguyen and Ulrich Abram

Inorganics 2024, 12(11), 295; https://doi.org/10.3390/inorganics12110295 - 17 Nov 2024

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Abstract

2,6-Dipicolinoylbis(N,N-dialkylthioureas) and H₂L^R2 react with uranyl salts and a supporting base (e.g., NEt₃) under formation of monomeric or oligomeric complexes of the compositions [UO₂(L^R2)(solv)] (solv = donor solvents) or [{UO₂(L [...] Read more.

2,6-Dipicolinoylbis(N,N-dialkylthioureas) and H₂L^R2 react with uranyl salts and a supporting base (e.g., NEt₃) under formation of monomeric or oligomeric complexes of the compositions [UO₂(L^R2)(solv)] (solv = donor solvents) or [{UO₂(L^R2)(µ₂-OMe)}₂]^2–. In such complexes, the uranyl ions are commonly coordinated by the “hard” O,N,O or N,N,N donor atom sets of the central ligand unit and the lateral sulfur donor atoms remain uncoordinated. Their individual structures, however, depend on the reaction conditions, particularly on the equivalents of NEt₃ used. An unprecedented, selective hydrolysis of the uranium-coordinating bis(thioureato) ligands results in an S/O donor atom exchange at exclusively one thiourea side-arm, when an excess of NEt₃ is used. The resulting trimeric uranyl complexes are isolated in fair yields and have a composition of [(UO₂)₃(L^2Et2)₂(µ₂–OR)(µ₃-O)]^–. H₂L^2Et2 represents the newly formed 2,6-dipicolinoyl(N,N-diethylthiourea)(N,N-diethylurea) and R = H, Me, or Et. {L^2Et2}^2– binds to the uranyl units via the pyridine ring, the dialkylurea arm, and the central carbonyl groups, while the thiourea unit remains uncoordinated. The central cores of the products consist of oxido-centered triangular {(UO₂)₃O}⁴⁺ units. The observed reactivity is metal-driven and corresponds mechanistically most probably to a classical metal-catalyzed hydrodesulfurization. The hydrolytic thiourea/urea conversion is only observed in the presence of uranyl ions. The products were isolated in crystalline form and studied spectroscopically and by X-ray diffraction. The experimental findings are accompanied by DFT calculations, which help to understand the energetic implications in such systems. Full article

(This article belongs to the Section Coordination Chemistry)

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17 pages, 3131 KiB

Open AccessArticle

Use of Chitosan and Chitosan–Magnetite Spheres for Arsenic Groundwater Removal: Factorial Designs as Tools to Optimize the Efficiency of Removal

by Mayra Hernández Trespalacios, María Florencia Mangiameli, Lina Gribaudo, María Inés Frascaroli and Juan Carlos González

Inorganics 2024, 12(11), 294; https://doi.org/10.3390/inorganics12110294 - 14 Nov 2024

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Abstract

The lack of access to drinking water is a problem affecting many regions worldwide. In Santa Fe, Argentina, the population uses groundwater as a source of drinking water. Unfortunately, it has high concentrations of As(V), which makes it unsuitable for consumption. Despite several [...] Read more.

The lack of access to drinking water is a problem affecting many regions worldwide. In Santa Fe, Argentina, the population uses groundwater as a source of drinking water. Unfortunately, it has high concentrations of As(V), which makes it unsuitable for consumption. Despite several methods for As(V) quantification and elimination, the high cost and technical difficulties in their implementation make many of them cost-ineffective, especially in small communities. In this work, a hybrid sorbent of magnetite–chitosan spheres (M-Q) is synthesized, and its sorption capacity is evaluated by employing groundwater with high conductivity (12.1 mS/cm) and hardness (1125 mg/L CaCO₃) and an As(V) concentration of 0.265 mg/L. A colorimetric analytical technique, which is sufficiently sensitive, simple, and economical to apply, is used for As(V) quantification. The experimental results indicate that the sorption capacity for As(V) removal is 80.1% (sorbent mass 0.466 g, time 85.3 min, and pH 5.9), with the advantage of the capability of being independent of its magnetic properties. The optimal experimental conditions for As(V) sorption (pH, time, and mass of the hybrid sorbent M-Q) are obtained by response surface factorial designs, which significantly reduce the total number of experiments and, at the same time, demonstrate that all the selected variables significantly affect the As(V) sorption percentage (response studied). Full article

(This article belongs to the Section Bioinorganic Chemistry)

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11 pages, 3935 KiB

Open AccessArticle

Hierarchically Electrodeposited Nickel/Graphene Coatings for Improved Corrosion Resistance of Ni Foam Flow Field in PEMFC

by Yuzhen Xia, Qibin Zuo, Chuanfu Sun, Guilin Hu and Baizeng Fang

Inorganics 2024, 12(11), 293; https://doi.org/10.3390/inorganics12110293 - 14 Nov 2024

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Abstract

Metal foams are promising materials for the flow fields of proton exchange membrane fuel cells (PEMFCs) because of excellent mass transport characteristics and high electronic conductivity. To resolve the corrosion problem in the acidic environment under high temperature, nickel/graphene (Ni/G) composite coatings with [...] Read more.

Metal foams are promising materials for the flow fields of proton exchange membrane fuel cells (PEMFCs) because of excellent mass transport characteristics and high electronic conductivity. To resolve the corrosion problem in the acidic environment under high temperature, nickel/graphene (Ni/G) composite coatings with hierarchical structures were electrodeposited on the surface of Ni foam. The effect of grain size and the distribution in the double layer was discussed. It was found that Ni/G5-10, with larger inner size and middle outer size, exhibited the best corrosion performance. Meanwhile, the corrosion current in the Tafel plots and the steady current density in constant potential analysis was lower than that obtained under steady and gradient currents. Combined with the results of XRD, XPS, and SEM, it was proven that a uniform and dense protective film was produced during the two-step electrodeposition. Moreover, the ICR value was 8.820 mΩ·cm², which met the requirement of 2025 DOE. Full article

(This article belongs to the Special Issue Advanced Electrocatalysis Materials Design: Innovations and Applications)

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39 pages, 8913 KiB

Open AccessReview

Inorganic-Based Nanoparticles and Biomaterials as Biocompatible Scaffolds for Regenerative Medicine and Tissue Engineering: Current Advances and Trends of Development

by Nabanita Saikia

Inorganics 2024, 12(11), 292; https://doi.org/10.3390/inorganics12110292 - 11 Nov 2024

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Abstract

Regenerative medicine amalgamates stem cell technology and tissue engineering strategies to replace tissues and organs damaged by injury, aging, ailment, and/or chronic conditions by leveraging the innate self-healing mechanism of the body. The term ‘regenerative medicine’ was coined by William A. Haseltine during [...] Read more.

Regenerative medicine amalgamates stem cell technology and tissue engineering strategies to replace tissues and organs damaged by injury, aging, ailment, and/or chronic conditions by leveraging the innate self-healing mechanism of the body. The term ‘regenerative medicine’ was coined by William A. Haseltine during a 1999 conference on Lake Como. Since its inception in 1968, the field has offered clinical benefits for the regeneration, repair, and restoration of bones, skin, cartilage, neural tissue, and the heart, as well as scaffold fabrication. The field of tissue engineering and regenerative medicine can vastly benefit from advancements in nanoscience and technology, particularly in the fabrication and application of inorganic-based nanoparticles and bionanomaterials. Due to the tunable intrinsic properties, i.e., size, topography, surface charge, and chemical stability, inorganic-based nanoparticles and biomaterials have surpassed traditional synthetic materials. Given the wide gamut of near-future applications of inorganic nanoparticles and biomaterials, this article gives an overview of the emerging roles in stem cell regenerative research, tissue engineering, artificial skin and cartilage regeneration, neural nerve injuries, 3D bioprinting, and development of new inorganic bio-scaffolds. The review also addresses the challenges related to the clinical application and tissue compatibility of inorganic nanoparticles and biomaterials, utilizing current state-of-the-art techniques. Full article

(This article belongs to the Special Issue Functional Inorganic Biomaterials for Molecular Sensing and Biomedical Applications)

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13 pages, 8864 KiB

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Nickel Foam-Supported FeP Encapsulated in N, P Co-Doped Carbon Matrix for Efficient Electrocatalytic Hydrogen Evolution

by Jianguo Zhong, Ting Zhang, Jianqiang Tian, Wei Gao and Yuxin Wang

Inorganics 2024, 12(11), 291; https://doi.org/10.3390/inorganics12110291 - 7 Nov 2024

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Abstract

Transition metal phosphides (TMPs) show great potential as catalysts for the hydrogen evolution reaction (HER). FeP stands out as an efficient and cost-effective non-noble metal-based HER catalyst. However, FeP tends to aggregate and suffer from instability during the reaction. To tackle these challenges, [...] Read more.

Transition metal phosphides (TMPs) show great potential as catalysts for the hydrogen evolution reaction (HER). FeP stands out as an efficient and cost-effective non-noble metal-based HER catalyst. However, FeP tends to aggregate and suffer from instability during the reaction. To tackle these challenges, we developed an efficient and straightforward approach to load metal-organic framework-derived N/P co-doped carbon-encapsulated FeP nanoparticles onto a nickel foam substrate (FeP@NPC/NF-450). This catalyst exhibits exceptional HER activity in 0.5 M H₂SO₄ and 1.0 M KOH solutions, with overpotentials of 68.3 mV and 106.1 mV at a current density of 10 mA cm⁻², respectively. Furthermore, it demonstrates excellent stability with negligible decay over 48 h in both acidic and alkaline solutions. The outstanding hydrogen evolution catalytic performance of FeP@NPC/NF-450 is mainly due to the N, P co-doped carbon matrix, which safeguards the FeP nanoparticles from aggregation and surface oxidation. Consequently, this enhances the availability of active sites during the hydrogen evolution reaction (HER), leading to improved stability. Moreover, introducing nickel foam offers a larger specific surface area and enhances charge transfer rates. This study provides a reference method for preparing stable and highly active electrocatalysts for hydrogen evolution. Full article

(This article belongs to the Special Issue Feature Papers in Inorganic Materials 2024)

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14 pages, 3617 KiB

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Effect of Doping ZrO₂ on Structural and Thermal Properties

by Mirela Petriceanu, Florentina Gabriela Ioniță, Radu Robert Piticescu, Adrian Ionuț Nicoară, Alexandru Cristian Matei, Miruna Adriana Ioța, Ioan Albert Tudor, Ștefania Caramarin and Cristina Florentina Ciobota

Inorganics 2024, 12(11), 290; https://doi.org/10.3390/inorganics12110290 - 6 Nov 2024

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Abstract

The aim of this paper was to investigate the structure and thermal properties of zirconia ceramics co-doped with rare earth (RE) elements in equimolar concentrations. We prepared (1 − x)ZrO₂ − x(yLa₂O₃ + yNd₂O₃ + ySm [...] Read more.

The aim of this paper was to investigate the structure and thermal properties of zirconia ceramics co-doped with rare earth (RE) elements in equimolar concentrations. We prepared (1 − x)ZrO₂ − x(yLa₂O₃ + yNd₂O₃ + ySm₂O₃ + yGd₂O₃ + yYb₂O₃) (x = 0.2; y = 0.2) powders by a hydrothermal method in mild conditions (200 °C, 2 h, 60–100 atm.) The powder was analyzed by XRD, SEM-EDAX, BET, and FT-IR after synthesis and heat treatments at 1200 °C and 1500 °C. The samples exhibit good thermal stability, with a single cubic phase presented after heat treatment at 1500 °C. The compound exhibits a low thermal conductivity (0.61 W·m⁻¹·K⁻¹), a low heat capacity (0.42 J·g⁻¹K⁻¹), and a low thermal diffusivity (0.34 mm²·s⁻¹). The values are lower than reported for conventional RE-doped zirconia. Full article

(This article belongs to the Special Issue Novel Functional Ceramics)

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14 pages, 4411 KiB

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Fabrication of Two-Dimensional Bi₂MoO₆ Nanosheet-Decorated Bi₂MoO₆/Bi₄O₅Br₂ Type II Heterojunction and the Enhanced Photocatalytic Degradation of Antibiotics

by Fengshu Kang, Gaidong Sheng, Xiaolong Yang and Yan Zhang

Inorganics 2024, 12(11), 289; https://doi.org/10.3390/inorganics12110289 - 4 Nov 2024

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Abstract

This article successfully synthesized a series of Bi₂MoO₆/Bi₄O₅Br₂ heterojunctions using a two-step solvothermal method followed by calcination, and the photocatalytic activity by degradation of tetracycline hydrochloride (TC) was investigated. Compared with pure Bi₄ [...] Read more.

This article successfully synthesized a series of Bi₂MoO₆/Bi₄O₅Br₂ heterojunctions using a two-step solvothermal method followed by calcination, and the photocatalytic activity by degradation of tetracycline hydrochloride (TC) was investigated. Compared with pure Bi₄O₅Br₂ and Bi₂MoO₆, a series of Bi₂MoO₆/Bi₄O₅Br₂ heterojunctions exhibit higher photocatalytic activity, which can be attributed to the heterostructures with strong interfacial interaction, improving the charge separation. The 2% Bi₂MoO₆/Bi₄O₅Br₂ heterojunction shows the best photocatalytic activity under visible light irradiation, which is 1.9 times and 1.8 times that of Bi₂MoO₆ and Bi₄O₅Br₂, respectively. In addition, cyclic experiments have shown that 2% Bi₂MoO₆/Bi₄O₅Br₂ heterojunction has high stability, with a degradation efficiency only decreasing by 3% after 5 cycles. From the capture agent experiment and ESR test, it can be seen that ·O₂⁻ and h⁺ are the main active species. A possible photocatalytic mechanism of 2% Bi₂MoO₆/Bi₄O₅Br₂ heterojunction under visible light irradiation was proposed. Full article

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

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15 pages, 9735 KiB

Open AccessArticle

Electrochemical Performances of a Solid Oxide Electrolysis Short Stack Under Multiple Steady-State and Cycling Operating Conditions

by Qinhui Ma, Yuhang Zuo, Kaifeng Lu, Yangyiming Rong, Wei Su, Hanming Chen and Xinhai Xu

Inorganics 2024, 12(11), 288; https://doi.org/10.3390/inorganics12110288 - 4 Nov 2024

Viewed by 656

Abstract

Solid oxide electrolysis cells (SOECs) are increasingly utilized in hydrogen production from renewable energy sources, yet high degradation rates and unclear degradation mechanisms remain significant barriers to their large-scale application. Consequently, endurance testing of stacks under various operating conditions and studying the degradation [...] Read more.

Solid oxide electrolysis cells (SOECs) are increasingly utilized in hydrogen production from renewable energy sources, yet high degradation rates and unclear degradation mechanisms remain significant barriers to their large-scale application. Consequently, endurance testing of stacks under various operating conditions and studying the degradation mechanisms associated with these conditions is imperative. However, due to the generally poor performance consistency among stacks, multi-condition data from numerous stacks lack reliability. In this experimental study, having established a specific SOEC stack’s performance and optimal conditions, durability tests under varied conditions, including various current densities, current operation modes (cyclic or constant current), fuel utilization rates, and temperature cycles were conducted. Electrochemical analysis tools like electrochemical impedance spectroscopy and distribution of relaxation time were employed to analyze the causes of voltage fluctuations under high current densities. The results confirmed that the SOEC stack could handle current cycling at low current densities and constant-current electrolysis at high current densities and withstand at least two temperature cycles. Full article

(This article belongs to the Special Issue Advanced Materials and Enhanced Performance of Solid Oxide Fuel Cells/Electrolyzers)

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12 pages, 1575 KiB

Open AccessArticle

Arene Ruthenium Complexes Specifically Inducing Apoptosis in Breast Cancer Cells

by Adriana Grozav, Thomas Cheminel, Ancuta Jurj, Oana Zanoaga, Lajos Raduly, Cornelia Braicu, Ioana Berindan-Neagoe, Ovidiu Crisan, Luiza Gaina and Bruno Therrien

Inorganics 2024, 12(11), 287; https://doi.org/10.3390/inorganics12110287 - 2 Nov 2024

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Abstract

Monocationic arene ruthenium complexes (RuL₁–RuL₄) incorporating phenothiazinyl-hydrazinyl-thiazole ligands (L₁–L₄) have been synthesized, characterized and evaluated as anticancer agents. Their cytotoxicity, antiproliferative activity and alteration of apoptotic gene expression were studied on [...] Read more.

Monocationic arene ruthenium complexes (RuL₁–RuL₄) incorporating phenothiazinyl-hydrazinyl-thiazole ligands (L₁–L₄) have been synthesized, characterized and evaluated as anticancer agents. Their cytotoxicity, antiproliferative activity and alteration of apoptotic gene expression were studied on three cancer cell lines, a double positive breast cancer cell line MCF-7 and two triple negative breast cancer cell lines Hs578T and MDA-MB-231. All arene ruthenium complexes were able to reduce the viability of the breast cancer cell lines, with the highest cytotoxicities being recorded for the [(p-cymene)RuL₃Cl]⁺ (RuL₃) complex on the MCF-7 (IC₅₀ = 0.019 µM) and Hs578T cell lines (IC₅₀ = 0.095 µM). In the double positive MCF-7 breast cancer cells, the complexes [(p-cymene)RuL₁Cl]⁺ (RuL₁) and [(p-cymene)RuL₂Cl]⁺ (RuL₂) significantly upregulated pro-apoptotic genes including BAK, FAS, NAIP, CASP8, TNF, XIAP and BAD, while downregulating TNFSF10. In the triple negative breast cancer cell line Hs578T, RuL₁ reduced TNFSF-10 and significantly upregulated BAK, CASP8, XIAP, FADD and BAD, while complex RuL₂ also increased BAK and CASP8 expression, but had limited effects on other genes. The triple negative MDA-MB-231 cancer cells treated with RuL₁ upregulated NOD1 and downregulated p53, while RuL₂ significantly downregulated p53, XIAP and TNFSF10, with minor changes in other genes. The significant alterations in the expression of key apoptotic genes suggest that such complexes have the potential to target cancer cells. Full article

(This article belongs to the Special Issue Noble Metals in Medicinal Inorganic Chemistry)

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24 pages, 6781 KiB

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A Structure and Magnetism Study of {Mn^II₃Mn^IVLn^III₃} Coordination Complexes with Ln = Dy, Yb

by Victoria Mazalova, Tatiana Asanova, Igor Asanov and Petra Fromme

Inorganics 2024, 12(11), 286; https://doi.org/10.3390/inorganics12110286 - 31 Oct 2024

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Abstract

We report the research results of polynuclear complexes consisting of 3d-4f mixed-metal cores that are maintained by acetate ligands and multidentate Schiff base ligands with structurally exposed thioether groups. The presence of the latter at the periphery of these neutral compounds enables their [...] Read more.

We report the research results of polynuclear complexes consisting of 3d-4f mixed-metal cores that are maintained by acetate ligands and multidentate Schiff base ligands with structurally exposed thioether groups. The presence of the latter at the periphery of these neutral compounds enables their anchoring onto substrate surfaces. Specifically, we investigated the electronic and magnetic properties as well as the structural arrangement in {Mn^II₃Mn^IVLn^III₃} with Ln = Dy, Yb coordination complexes using various complementary methods. We studied the electronic and atomic structure of the target compounds using the XAS and XES techniques. The molecular structures of the compounds were determined using density functional theory, and the magnetic data were obtained as a function of the magnetic field. Using the XMCD method, we followed the changes in the electronic and magnetic properties of adsorbed magnetic compounds induced by the reaction of ligands through interaction with the substrate. The complexes show antiferromagnetic exchange interactions between Mn and Ln ions. The spectroscopic analyses confirmed the structural and electronic integrity of complexes in organic solution. This study provides important input for a full understanding of the dependence of the magnetic properties and the molecule–substrate interaction of single adsorbed molecules on the type of ligands. It highlights the importance of chemical synthesis for controlling and tailoring the magnetic properties of metalorganic molecules for their use as optimized building blocks of future molecular spin electronics. Full article

(This article belongs to the Section Coordination Chemistry)

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3 pages, 156 KiB

Open AccessEditorial

Advances in Thermoelectric Materials—Bridging the Gap Between Discovery and Application

by Marco Fronzi, Paolo Mele and Giovanna Latronico

Inorganics 2024, 12(11), 285; https://doi.org/10.3390/inorganics12110285 - 31 Oct 2024

Viewed by 737

Abstract

Thermoelectric materials have gained considerable attention in recent years due to their ability to directly convert heat into electricity, making them a key focus in the development of sustainable energy technologies [...] Full article

(This article belongs to the Special Issue Advances of Thermoelectric Materials)

14 pages, 4853 KiB

Open AccessArticle

A New Bromo-Mn(II) Complex with 1,3,5-Triazine Derivative: Synthesis, Crystal Structure, DFT and Biological Studies

by Sara M. Khattab, Mezna Saleh Altowyan, Ayman El-Faham, Assem Barakat, Matti Haukka, Morsy A. M. Abu-Youssef and Saied M. Soliman

Inorganics 2024, 12(11), 284; https://doi.org/10.3390/inorganics12110284 - 31 Oct 2024

Viewed by 654

Abstract

The crystal structure and topology analyses of a new bromo-Mn(II) complex with 2,4-bis(3,5dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (MBPT) were reported. Its structure was confirmed using single-crystal X-ray diffraction to create the formula [Mn(MBPT)Br(H₂O)₂]ClO₄. Its crystal system was [...] Read more.

The crystal structure and topology analyses of a new bromo-Mn(II) complex with 2,4-bis(3,5dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (MBPT) were reported. Its structure was confirmed using single-crystal X-ray diffraction to create the formula [Mn(MBPT)Br(H₂O)₂]ClO₄. Its crystal system was monoclinic and its space group was p2₁. The Mn(II) was coordinated with MBPT as a NNN-pincer ligand, with one bromide ion in the equatorial plane. The two axial terminals were occupied by two trans water molecules. H…H, N…H, Br…H, C…H and O…H were the predominant intermolecular contacts, while Br…H, O…H and C…O were the significant contacts based on Hirshfeld analysis. Moreover, anion–ᴨ interaction was found between C(s-triazine) and O(perchlorate). This complex had better antioxidant activity than the free ligand (MBPT). In addition, the cytotoxicity of the [Mn(MBPT)Br(H₂O)₂]ClO₄ complex showed better results against HepG-2 and MCF-7 cells, recording IC₅₀ values of 31.11 ± 2.04 and 50.05 ± 2.16 µM, respectively, compared to the free ligand (IC₅₀ = 671.44 ± 21.41 and 1113.55 ± 29.77 µM). In comparison to cis-platin as a reference drug, the IC₅₀ values were 63 and 80 μM, respectively, which indicated the promising anticancer activity of the studied compound against both cell lines. In terms of the safety of normal cells, the Mn(II) complex recorded a high IC₅₀ value of 359.10 ± 8.72 µM against the WI-38 non-cancerous cell line. The complex showed better activity towards Staphylococcus aureus, Bacillus subtilis, and Proteus vulgaris relative to the free MBPT, but had low to moderate activity compared to Gentamycin as an antibacterial positive control. Full article

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12 pages, 2035 KiB

Open AccessArticle

Catalytic Behavior of NHC–Silver Complexes in the Carboxylation of Terminal Alkynes with CO₂

by Assunta D’Amato, Marco Sirignano, Francesco Viceconte, Pasquale Longo and Annaluisa Mariconda

Inorganics 2024, 12(11), 283; https://doi.org/10.3390/inorganics12110283 - 30 Oct 2024

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Abstract

A number of N-heterocyclic carbene–silver compounds (NHCs)AgX were tested in the direct carboxylation of terminal alkynes using carbon dioxide as the C1 carbon feedstock. The reactions proceed at a pressure of 1 atm of CO₂ at room temperature, in the presence of [...] Read more.

A number of N-heterocyclic carbene–silver compounds (NHCs)AgX were tested in the direct carboxylation of terminal alkynes using carbon dioxide as the C1 carbon feedstock. The reactions proceed at a pressure of 1 atm of CO₂ at room temperature, in the presence of Cs₂CO₃, and using silver–NHC complexes as catalysts. Thus, phenylacetylene and several alkynes are converted to the corresponding propiolic acids in good to high conversions. The activity of the catalysts is strongly influenced by the substituents on the NHC backbone and the nature of the counterion. Specifically, the most active compound exhibits iodide as the counterion and is stabilized by a benzimidazole derivative. After 24 h of reaction, a quantitative conversion is obtained utilizing DMF as the solvent and phenylacetylene as the substrate. Full article

(This article belongs to the Special Issue N-Heterocyclic Carbene Metal Complexes: Synthesis, Properties and Applications, 2nd Edition)

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14 pages, 3523 KiB

Open AccessArticle

Comparative Study of Docking Tools for Evaluation of Potential Copper Metallodrugs and Their Interaction with TMPRSS2

by Sergio Vázquez-Rodríguez, Diego Ramírez-Contreras, Lisset Noriega, Amalia García-García, Brenda L. Sánchez-Gaytán, Francisco J. Meléndez, Walter Filgueira de Azevedo, Jr., María Eugenia Castro and Enrique González-Vergara

Inorganics 2024, 12(11), 282; https://doi.org/10.3390/inorganics12110282 - 30 Oct 2024

Viewed by 651

Abstract

COVID-19 has caused over seven million deaths globally due to its high transmission rate. The virus responsible for the disease requires a transmembrane protease serine type II (TMPRSS2-7MEQ) to infiltrate host cells and has been linked to several cancers, particularly prostate cancer. To [...] Read more.

COVID-19 has caused over seven million deaths globally due to its high transmission rate. The virus responsible for the disease requires a transmembrane protease serine type II (TMPRSS2-7MEQ) to infiltrate host cells and has been linked to several cancers, particularly prostate cancer. To investigate COVID-19 potential therapies, a series of Casiopeina-like copper complexes containing 1,10-Phenanthroline and amino acids were investigated as TMPRSS2 inhibitors. The molecular structures of twelve Phenanthroline copper complexes were calculated, and their global reactivity indices were analyzed using DFT and conceptual DFT methods. Three molecular docking algorithms were employed to identify the most effective inhibitors by examining their interactions with amino acid residues in the target protein’s catalytic activity triad (Asp345, His296, and Ser441). All complexes are docked above the catalytic site, blocking the interaction with substrates. The Phenanthroline complexes showed better interactions than the Bipyridine complexes, likely due to increased hydrophobic contacts. Analogs’ cationic nature and amino acids’ basic side chains bring them near the active site by interacting with Asp435. The top complexes in this study contain Ornithine, Lysine, and Arginine, making them promising alternatives for researching new drugs for COVID-19 and cancers like prostate cancer. Full article

(This article belongs to the Special Issue Evaluation of the Potential Biological Activity of Metallo-Drugs)

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14 pages, 4663 KiB

Open AccessArticle

Core/Shell ZnO/TiO₂, SiO₂/TiO₂, Al₂O₃/TiO₂, and Al_1.9Co_0.1O₃/TiO₂ Nanoparticles for the Photodecomposition of Brilliant Blue E-4BA

by Mahboubeh Dolatyari, Mehdi Tahmasebi, Sudabeh Dolatyari, Ali Rostami, Armin Zarghami, Ashish Yadav and Axel Klein

Inorganics 2024, 12(11), 281; https://doi.org/10.3390/inorganics12110281 - 30 Oct 2024

Viewed by 854

Abstract

The synthesis and characterization of ZnO/TiO₂, SiO₂/TiO₂, Al₂O₃/TiO₂, and Al_1.9Co_0.1O₃/TiO₂ core/shell nanoparticles (NPs) is reported. The NPs were used for photocatalytic degradation of brilliant [...] Read more.

The synthesis and characterization of ZnO/TiO₂, SiO₂/TiO₂, Al₂O₃/TiO₂, and Al_1.9Co_0.1O₃/TiO₂ core/shell nanoparticles (NPs) is reported. The NPs were used for photocatalytic degradation of brilliant blue E-4BA under UV and visible light irradiation, monitored by high-performance liquid chromatography and UV-vis absorption spectroscopy. The size of the NPs ranged from 10 to 30 nm for the core and an additional 3 nm for the TiO₂ shell. Al₂O₃/TiO₂ and Al_1.9Co_0.1O₃/TiO₂ showed superior degradation under UV and visible light compared to ZnO/TiO₂ and SiO₂/TiO₂ with complete photodecomposition of 20 ppm dye in 20 min using a 10 mg/100 mL photocatalyst. The “Co-doped” Al_1.9Co_0.1O₃/TiO₂ NPs show the best performance under visible light irradiation, which is due to increased absorption in the visible range. DFT-calculated band structure calculations confirm the generation of additional electronic levels in the band gap of γ-Al₂O₃ through Co³⁺ ions. This indicates that Co-doping enhances the generation of electron–hole pairs after visible light irradiation. Full article

(This article belongs to the Special Issue New Advances into Nanostructured Oxides, 2nd Edition)

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24 pages, 8710 KiB

Open AccessArticle

Structural, Antioxidant, and Protein/DNA-Binding Properties of Sulfate-Coordinated Ni(II) Complex with Pyridoxal-Semicarbazone (PLSC) Ligand

by Violeta Jevtovic, Luka Golubović, Odeh A. O. Alshammari, Munirah Sulaiman Alhar, Tahani Y. A. Alanazi, Aleksandra Radulović, Đura Nakarada, Jasmina Dimitrić Marković, Aleksandra Rakić and Dušan Dimić

Inorganics 2024, 12(11), 280; https://doi.org/10.3390/inorganics12110280 - 30 Oct 2024

Viewed by 635

Abstract

The pyridoxal-semicarbazone (PLSC) ligand and its transition metal complexes have shown significant biological activity. In this contribution, a novel nickel(II)-PLSC complex, [Ni(PLSC)(SO₄)(H₂O)₂], was obtained, and its structure was determined by X-ray crystallographic analysis, FTIR, and UV-VIS spectroscopy. [...] Read more.

The pyridoxal-semicarbazone (PLSC) ligand and its transition metal complexes have shown significant biological activity. In this contribution, a novel nickel(II)-PLSC complex, [Ni(PLSC)(SO₄)(H₂O)₂], was obtained, and its structure was determined by X-ray crystallographic analysis, FTIR, and UV-VIS spectroscopy. The sulfate ion is directly coordinated to the central metal ion. The intermolecular stabilization interactions were examined using Hirshfeld surface analysis. The crystal structure was optimized by a B3LYP functional using two pseudopotentials for nickel(II) (LanL2DZ and def2-TZVP) together with a 6-311++G(d,p) basis set for non-metallic atoms. The experimental and theoretical bond lengths and angles were compared, and the appropriate level of theory was determined. The stabilization interactions within the coordination sphere were investigated by the Quantum Theory of Atoms in Molecules (QTAIM). The antioxidant activity towards hydroxyl and ascorbyl radicals was measured by EPR spectroscopy. The interactions between Human Serum Albumin (HSA) and the complex were examined by spectrofluorimetric titration and a molecular docking study. The mechanism of binding to DNA was analyzed by complex fluorescence quenching, potassium iodide quenching, and ethidium bromide displacement studies in conjunction with molecular docking simulations. Full article

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

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15 pages, 2918 KiB

Open AccessCommunication

Monodentate Ligands in X-Cu(I)-Y Complexes—Structural Aspects

by Milan Melník, Veronika Mikušová and Peter Mikuš

Inorganics 2024, 12(11), 279; https://doi.org/10.3390/inorganics12110279 - 30 Oct 2024

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Abstract

This structural study examines over 102 coordinate Cu(I) complexes with compositions such as C-Cu-Y (Y=HL, OL, NL, SL, SiL, BL, PL, Cl, Br, I, AlL, or SnL), N-Cu-Y (Y=OL, Cl), S-Cu-Y (Y=Cl, Br, I), P-Cu-Y (Y=Cl, I), and Se-Cu-Y (Y=Br, I). These complexes [...] Read more.

This structural study examines over 102 coordinate Cu(I) complexes with compositions such as C-Cu-Y (Y=HL, OL, NL, SL, SiL, BL, PL, Cl, Br, I, AlL, or SnL), N-Cu-Y (Y=OL, Cl), S-Cu-Y (Y=Cl, Br, I), P-Cu-Y (Y=Cl, I), and Se-Cu-Y (Y=Br, I). These complexes crystallize into three different crystal classes: monoclinic (seventy-two instances), triclinic (twenty-eight instances), and orthorhombic (eight instances). The Cu-L bond length increases with the covalent radius of the ligating atom. There are two possible geometries for coordination number two: linear and bent. A total of 21 varieties of inner coordination spheres exist, categorized into two hetero-types (C-Cu-Y, i.e., organometallic compounds and X-Cu-Y, i.e., coordination compounds). The structural parameters of hetero Cu(I) complexes were compared with trans-X-Cu (I)-X (homo) complexes and analyzed. The maximum deviations from linearity (180.0°) are, on average, 10.3° for Br-Cu(I)-Br, 16.6° for C-Cu(I)-Sn, and 35.5° for P-Cu(I)-I. These results indicate that ligand properties influence deviation from linearity, increasing in the order of hard < borderline < soft. Full article

(This article belongs to the Special Issue Feature Papers in Organometallic Chemistry 2024)

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15 pages, 2861 KiB

Open AccessReview

Emerging New-Generation Semiconductor Single Crystals of Metal Halide Perovskites for Radiation Detection

by Guigen Luo, Min Peng, Zhibin Yang, Chungming Paul Chu and Zhengtao Deng

Inorganics 2024, 12(11), 278; https://doi.org/10.3390/inorganics12110278 - 30 Oct 2024

Viewed by 978

Abstract

Radiation detection uses semiconductor materials to convert high-energy photons into charge (direct detection) or low-energy photons (indirect detection), and it has a wide range of applications in nuclear physics, medical imaging, astronomical detection, homeland security, and other fields. Metal halide perovskites have the [...] Read more.

Radiation detection uses semiconductor materials to convert high-energy photons into charge (direct detection) or low-energy photons (indirect detection), and it has a wide range of applications in nuclear physics, medical imaging, astronomical detection, homeland security, and other fields. Metal halide perovskites have the advantages of high frequency number, high carrier mobility, high defect tolerance, low defect density, adjustable band gap, and fast light response, and they have wide application prospects in the field of radiation detection. However, the research is still in its infancy stage, and it is far from meeting the requirements of industrial application. This paper focuses on the advantages of metal halide perovskite single-crystal materials in both semiconductors-based direct conversion detection and scintillator-based indirect detection as well as the latest progress in this promising field. This paper not only introduces the latest application of lead halide perovskite monocrystalline materials in high-energy electromagnetic radiation detection (X-ray and γ-rays), but it also introduces the latest development of α-particle/β-particle/neutron detection. Finally, this paper points out the challenges and future prospects of metal halide perovskite single-crystal materials in radiation detection. Full article

(This article belongs to the Section Inorganic Solid-State Chemistry)

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15 pages, 2913 KiB

Open AccessReview

Late Transition Metal Olefin Polymerization Catalysts Derived from 8-Arylnaphthylamines

by Zonglin Qiu, Wenyan Wang, Handou Zheng, Dengfei Wang, Xinglong Zhao, Guangshui Tu, Jiahao Yang and Haiyang Gao

Inorganics 2024, 12(11), 277; https://doi.org/10.3390/inorganics12110277 - 28 Oct 2024

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Abstract

Late transition metal catalysts represent a significant class of olefin polymerization catalysts that have played an essential role in advancing the polyolefin industry owing to their highly tunable ligands and low oxophilicity. A key feature for the design of late transition metal catalysts [...] Read more.

Late transition metal catalysts represent a significant class of olefin polymerization catalysts that have played an essential role in advancing the polyolefin industry owing to their highly tunable ligands and low oxophilicity. A key feature for the design of late transition metal catalysts lies in the steric bulk of the o-aryl substituents. Bulky 8-arylnaphthylamines have emerged as a promising aniline candidate for conducting high-performance catalysts by introducing axially steric hindrance around the metal center. This review focuses on late transition metal (Ni, Pd, Fe) catalysts derived from 8-arylnaphthylamines, surveying their synthesis, structural features, and catalytic applications in olefin (co)polymerizations. Additionally, the relationship between catalyst structure and catalytic performance is discussed, highlighting how these unique ligand systems influence polymerization activity, molecular weight, and polymer branching. Full article

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

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15 pages, 10179 KiB

Open AccessArticle

Adsorption Studies of Ternary Metal Ions (Cs⁺, Sr²⁺, and Co²⁺) from Water Using Zeolite@Magnetic Nanoparticles (Z@Fe₃O₄ NPs)

by Tung Van Nguyen, Lien Thi Nguyen, Ha Thi Thu Nguyen and Thu-Huong Le

Inorganics 2024, 12(11), 276; https://doi.org/10.3390/inorganics12110276 - 25 Oct 2024

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Abstract

The mixture of three metal ions (Cs⁺, Sr²⁺, and Co²⁺) is commonly found in radioactive waste, which induces several negative health effects. The removal of multiple metal ions is a true challenge for researchers due to the [...] Read more.

The mixture of three metal ions (Cs⁺, Sr²⁺, and Co²⁺) is commonly found in radioactive waste, which induces several negative health effects. The removal of multiple metal ions is a true challenge for researchers due to the competitive adsorption of ions onto adsorbents. In this study, three metal ions, namely Cs⁺, Sr²⁺, and Co²⁺, have been successfully removed simultaneously from water using zeolite@magnetic nanoparticles (Z@Fe₃O₄ NPs). The optimized condition for the adsorption of ternary metal ions was obtained at an adsorbent weight of 0.2, pH of 6.0~7.0, and contact time of 60 min. The adsorption mechanism of ternary metal ions onto the surface of Z@Fe₃O₄ NPs was studied using the Pseudo-first-order, Pseudo-second-order, Elovich, and Intra-particle diffusion models. The Dubinin–Radushkevich Temkin, Freundlich, and Langmuir isotherm models were used to study the isotherm adsorption. The ternary metal ion adsorption (Cs⁺, Sr²⁺, and Co²⁺) on Z@Fe₃O₄ NPs was followed by the Pseudo-second-order model (PSO) with correlation coefficient (R²) range of 0.9826–0.9997. Meanwhile, the adsorption isotherms of ternary metal ions on Z@Fe₃O₄ NPs were in line with the Langmuir model with R² values higher than 0.9206, suggesting monolayer chemisorption with maximum adsorption capacities of 48.31, 15.02, and 10.41 mg/g for Cs⁺, Sr²⁺, and Co²⁺, respectively. Thus, the selectivity trend in the ternary metal ions system towards the Z@Fe₃O₄ NPs is observed to be Cs⁺ > Sr²⁺ > Co²⁺, which indicates that the competitive effect of Cs⁺ is the strongest compared to Sr²⁺ and Co²⁺ions. Full article

(This article belongs to the Special Issue Mixed Metal Oxides II)

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40 pages, 7283 KiB

Open AccessReview

Recent Advances in Low Valent Thorium and Uranium Chemistry

by Nikolaos Tsoureas and Ioannis Vagiakos

Inorganics 2024, 12(11), 275; https://doi.org/10.3390/inorganics12110275 - 24 Oct 2024

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Abstract

The synthesis, isolation, and characterisation of well-defined low-valent actinide complexes are reviewed with a main focus on compounds featuring uranium and thorium metal centres in formal oxidation states ≤ +3. The importance of the ligand environment in enabling access to these highly reactive [...] Read more.

The synthesis, isolation, and characterisation of well-defined low-valent actinide complexes are reviewed with a main focus on compounds featuring uranium and thorium metal centres in formal oxidation states ≤ +3. The importance of the ligand environment in enabling access to these highly reactive species, as well as its influence on ground state electronic configurations and their reactivity, are emphasised. Furthermore, we highlight cyclic voltammetry (C.V.) studies as a more widely used method that can guide the synthesis of these highly reducing species. Full article

(This article belongs to the Special Issue Feature Papers in Organometallic Chemistry 2024)

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24 pages, 5128 KiB

Open AccessArticle

Achieving Ultra-Low-Sulfur Model Diesel Through Defective Keggin-Type Heteropolyoxometalate Catalysts

by Natali de la Fuente, Jin An Wang, Lifang Chen, Miguel A. Valenzuela, Luis E. Noreña, Elizabeth Rojas, Julio González, Mu He, Jiang Peng and Xiaolong Zhou

Inorganics 2024, 12(11), 274; https://doi.org/10.3390/inorganics12110274 - 23 Oct 2024

Viewed by 763

Abstract

Various Keggin-type heteropolyoxometalate catalysts with structural defects and surface acidity were synthesized by immobilizing 12-phosphotungstic acid (HPW) on mesoporous SBA−15, to produce near-zero-sulfur diesel fuel. As the calcination temperature increased, the W=O and the corner-shared W–O–W bonds in the Keggin unit partially [...] Read more.

Various Keggin-type heteropolyoxometalate catalysts with structural defects and surface acidity were synthesized by immobilizing 12-phosphotungstic acid (HPW) on mesoporous SBA−15, to produce near-zero-sulfur diesel fuel. As the calcination temperature increased, the W=O and the corner-shared W–O–W bonds in the Keggin unit partially broke, creating oxygen defects, as evidenced by the Rietveld refinement and in situ FTIR characterization. All the catalysts contained Lewis (L) and Brønsted (B) acid sites, with L acidity predominant. The relative intensity of the IR band (I₉₈₀) of W=O bond inversely correlated with the number of L acid sites as the calcination temperature varied, suggesting that oxygen defects contributed to the Lewis acid sites formation. In the oxidation of dibenzothiophene (DBT) in a model diesel within a biphasic system, DBT conversion exceeded 99% under the optimal reaction conditions (reaction temperature 70 °C, reaction time 60 min, H₂O₂/sulfur molar ratio 8, H₂O₂/formic acid molar ratio 1.5, catalyst concentration 2 mg/mL). The influence of fuel composition and addition of indole and 4,6-DMDBT on DBT oxidation were also evaluated. Indole and cyclohexene negatively impacted the DBT oxidative removal. Oxygen defects served as active centers for competitive adsorption of sulfur compound and oxidant. Both L and B acid sites were involved in transferring O atom from peroxophosphotungstate complex to sulfur in DBT, resulting in DBTO₂ sulfone, which was immediately extracted by polar acetonitrile. This study confirms that structural defects and surface acidity are crucial in the deep oxidative desulfurization (ODS) reaction, and in enabling the simultaneous oxidation and separation of refractory organosulfur compounds in a highly efficient model diesel. Full article

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12 pages, 24978 KiB

Open AccessArticle

Enhancements in Hydrogen Storage Properties of Magnesium Hydride Supported by Carbon Fiber: Effect of C–H Interactions

by Quan Yang, Xiansong Jia, Zhikang Qin, Xiaoli Ding and Yongtao Li

Inorganics 2024, 12(11), 273; https://doi.org/10.3390/inorganics12110273 - 23 Oct 2024

Viewed by 678

Abstract

Carbon-based materials with excellent catalytic activity provide new ideas for the development of magnesium-based hydrogen storage. C-H bonding interactions may play a key role in performance improvement. In this work, we comprehensively compare the magnesium-carbon cloth composites (CC) prepared by method of dry [...] Read more.

Carbon-based materials with excellent catalytic activity provide new ideas for the development of magnesium-based hydrogen storage. C-H bonding interactions may play a key role in performance improvement. In this work, we comprehensively compare the magnesium-carbon cloth composites (CC) prepared by method of dry ball milling and wet impregnation. The results were that the hydrogen release activation energy (E_a) of MgH₂@CC composites prepared by wet immersion method was 175.1 ± 19.5 kJ·mol⁻¹, which was lower than that of pure MgH₂ (E_a = 213.9 ± 6.4 kJ·mol⁻¹), and the activation energy of MgH₂-CC composites prepared by ball milling method was 137.3 ± 8.7 kJ·mol⁻¹, which provided better results. The kinetic enhancement should be attributed to C-H interactions. The presence of carbon carriers and electron transfer to reduce the activation energy of Mg-H bond fracture. These results will provide further insights into the promotion of hydrogen ab-/desorption from metal hydrides. Full article

(This article belongs to the Special Issue Feature Papers in Inorganic Materials 2024)

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12 pages, 2416 KiB

Open AccessArticle

Ultralight Cellulose-Derived Carbon Nanofibers from Freeze-Drying Emulsion Towards Superior Microwave Absorption

by Anran Li, Zongquan Li and Lei Qian

Inorganics 2024, 12(11), 272; https://doi.org/10.3390/inorganics12110272 - 23 Oct 2024

Viewed by 807

Abstract

Carbon nanofibers (CNFs) are usually prepared by the carbonization of cellulose aerogels obtained from freeze-drying. However, cellulose with low concentration (below 1 wt%) is required to maintain the good porosity of the aerogels due to the strong hydrogen bonding between the cellulose molecules. [...] Read more.

Carbon nanofibers (CNFs) are usually prepared by the carbonization of cellulose aerogels obtained from freeze-drying. However, cellulose with low concentration (below 1 wt%) is required to maintain the good porosity of the aerogels due to the strong hydrogen bonding between the cellulose molecules. In order to address this problem, here, ultralight cellulose-derived CNFs have been fabricated by freeze-drying cyclohexane (CHE)/cellulose nanofiber emulsions and carbonization. Field emission scanning electron microscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy are used to characterize the resulting CNFs. It is found that the CNFs consist of three-dimensional carbon networks, whose microstructure is easily adjusted by changing the CHE ratio (from 0 to 25 vol%) in the emulsions. The CNFs with high porosity are attributed to the fact that CHE as the oil phase can effectively weaken the hydrogen bonding and reduce the aggregation of the cellulose nanofibers. Carbon lattice defects and residual oxygen-containing functional groups are regarded as polarization centers, leading to the enhancement of dielectric loss. The conductive carbon networks also improve the conductive loss. All these factors improve the microwave absorption performance of the CNFs. So, the produced CNFs exhibit a superior electromagnetic wave performance with a minimum reflection loss of −42.18 dB and effective absorption bandwidth up to 4.9 GHz at 2 mm with a filling ratio of 2 wt%. This work provides a simple, low-cost, and sustainable synthesis route for CNFs used for ultralight high-performance microwave absorption materials. Full article

(This article belongs to the Special Issue Carbon Nanomaterials for Advanced Technology)

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Inorganics, Volume 12, Issue 11 (November 2024) – 27 articles

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