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Inorganics, Volume 11, Issue 7 (July 2023) – 50 articles

Cover Story (view full-size image): The substitution of iron for noble metals in photochemical and photophysical applications is challenging due to the rapid deactivation of short-lived catalytically active states. Inspired by the success of a cyclometalated iron(III) complex, phenyl-1H-pyrazole was explored as a bidentate ligand. This study introduces five complexes based on the tris(1-phenylpyrazolato-N,C2)iron(III) scaffold. Alongside the parental complex, four derivatives with meta-functionalization of the phenyl ring were investigated using single crystal diffractometry, UV-Vis spectroscopy and cyclic voltammetry. X-ray absorption and emission spectroscopy provided insights into the electronic structure with complementing DFT calculations. The ligand design produced overlapping MLCT and LMCT absorption bands, with suppressed emissive behaviour due to the low-lying MC states. View this paper
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9 pages, 958 KiB  
Article
Pr@C82 Metallofullerene: Calculated Isomeric Populations
by Zdeněk Slanina, Filip Uhlík, Takeshi Akasaka, Xing Lu and Ludwik Adamowicz
Inorganics 2023, 11(7), 313; https://doi.org/10.3390/inorganics11070313 - 24 Jul 2023
Viewed by 938
Abstract
Relative equilibrium populations of the five lowest-energy isolated-pentagon-rule (IPR) isomeric structures of Pr@C82 under high-temperature fullerene synthesis conditions were calculated with the Gibbs energy terms based on molecular characteristics derived using density functional theory (DFT) treatments (B3LYP/6-31+G*∼SDD energetics and B3LYP/6-31G [...] Read more.
Relative equilibrium populations of the five lowest-energy isolated-pentagon-rule (IPR) isomeric structures of Pr@C82 under high-temperature fullerene synthesis conditions were calculated with the Gibbs energy terms based on molecular characteristics derived using density functional theory (DFT) treatments (B3LYP/6-31+G*∼SDD energetics and B3LYP/6-31G*∼SDD entropy). Two leading isomers were identified, major Pr@C2v;9-C82 and minor Pr@Cs;6-C82. The calculated isomeric relative equilibrium populations agreed with observations. Full article
(This article belongs to the Special Issue Research on Metallofullerenes)
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16 pages, 3048 KiB  
Article
Structure–Function Relationship within Cu-Peptoid Electrocatalysts for Water Oxidation
by Guilin Ruan, Natalia Fridman and Galia Maayan
Inorganics 2023, 11(7), 312; https://doi.org/10.3390/inorganics11070312 - 24 Jul 2023
Viewed by 1176
Abstract
Water oxidation (WO) is the first step in the water-splitting process aiming at the production of hydrogen as a green renewable fuel. To successfully perform WO, potent strategies for overcoming the high energetic barrier and slow kinetics of this reaction are urgently required. [...] Read more.
Water oxidation (WO) is the first step in the water-splitting process aiming at the production of hydrogen as a green renewable fuel. To successfully perform WO, potent strategies for overcoming the high energetic barrier and slow kinetics of this reaction are urgently required. One such strategy is the use of molecular catalysis. Specifically, Cu-based catalysts have been highlighted over the last decade due to their stability and fast kinetics. Among them, Cu-peptoids, where peptoids are peptidomimetics akin to peptides and are N-substituted glycine oligomers, can act as stable and active catalysts for oxidation transformations including electrocatalytic WO. Previously, we suggested that a benzyl group incorporated as a side chain near the catalytic site within a Cu-peptoid electrocatalyst for WO has a structural role in the activity of the electrocatalyst in phosphate buffer (PBS). Herein, we aimed to test this hypothesis and understand how an incorporated structural element side chain affects WO. To this aim, we prepared a set of peptoid trimers each with a different structural element replacing the benzyl group by either naphthyl, cyclohexyl, benzyl, propyl chloride, or propyl side chains as well as a peptoid lacking a structural element. We studied the structure of their Cu complexes and tested these complexes as electrocatalysts for WO. We discovered that while all the peptoids self-assemble to form dinuclear Cu-peptoid complexes, the duplex that has no structural side chain, Cu2(BE)2, is structurally different from the others in the solid state. Moreover, Cu2(BE)2 remains dinuclear in a PBS at pH 11, while all the other duplexes are mononuclear in the PBS. Finally, though most of the complexes showed low electrocatalytic activity for WO, the dinuclear complex Cu2(BE)2 performed with the highest turnover frequency of 484 s−1. Nevertheless, this dinuclear complex slowly decomposes to the corresponding mononuclear complex as a more stable species during WO, while the other mononuclear complexes retain their structure in solution but display much slower kinetics (ca. 5 to 8 s−1) under the same conditions. Overall, our results demonstrate that bulkier side chains hamper the stability of dinuclear Cu-peptoids in a PBS, and hence, their efficiency as WO electrocatalysts is also hampered. Full article
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11 pages, 2379 KiB  
Article
MoO3 Solubility and Chemical Durability of V2O5-Bearing Borosilicate Glass
by Minako Nagata and Toru Sugawara
Inorganics 2023, 11(7), 311; https://doi.org/10.3390/inorganics11070311 - 24 Jul 2023
Cited by 1 | Viewed by 823
Abstract
In the vitrification of high-level radioactive liquid waste (HLW), the separation of sodium-molybdate melts is a problem because it reduces the chemical durability of the vitrified waste. A glass with both high MoO3 solubility and chemical durability is required for the safe [...] Read more.
In the vitrification of high-level radioactive liquid waste (HLW), the separation of sodium-molybdate melts is a problem because it reduces the chemical durability of the vitrified waste. A glass with both high MoO3 solubility and chemical durability is required for the safe disposal of radioactive waste. In this study, we investigate the effects of vanadium oxide on the phase separation of the molybdenum-rich phase and the water resistance of the resulting glass by phase equilibrium experiments and chemical durability test. Phase equilibrium experiments were performed on SiO2-B2O3-Al2O3-ZnO-CaO-Na2O-LiO2-MoO3 system glasses and on glasses with V2O5 added. The results showed that MoO3 solubility increased when V2O5 was added. The increase in MoO3 solubility in borosilicate melts may be associated with the viscosity-lowering effect of V2O5. Chemical durability tests were performed on borosilicate glass compositions obtained from phase equilibrium experiments. The normalized leaching rates of V2O5-bearing glasses were higher than those of other glasses. This is due to the higher network modifier/network former ratio of the glass tested. The normalized elemental mass loss of glass containing waste components increases with increasing leaching duration. This suggests that the waste component prevents the formation of a gel layer at the reaction front. Full article
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13 pages, 1153 KiB  
Article
Redox Targets for Phosphine–Boranes
by Yonatan Morocz, Rachel E. Greben and Leonard A. Levin
Inorganics 2023, 11(7), 310; https://doi.org/10.3390/inorganics11070310 - 22 Jul 2023
Cited by 1 | Viewed by 1167
Abstract
Understanding the complex mechanisms underlying redox-mediated biological processes is a fundamental pillar of cellular biology. We describe the identification and quantification of disulfide formation and reduction in response to phosphine–borane complexes. We illustrate the specific cysteine reduction effects of the novel phosphine–borane complex [...] Read more.
Understanding the complex mechanisms underlying redox-mediated biological processes is a fundamental pillar of cellular biology. We describe the identification and quantification of disulfide formation and reduction in response to phosphine–borane complexes. We illustrate the specific cysteine reduction effects of the novel phosphine–borane complex bis(3-propionic acid methyl ester) phenylphosphine–borane complex (PB1) on cultured 661W cells. A total of 1073 unique protein fragments from 628 unique proteins were identified and quantified, of which 13 were found to be statistically significant in comparison to control cells. Among the 13 identified proteins were Notch1, HDAC1, UBA1, USP7, and subunits L4 and L7 of the 60S ribosomal subunit, all of which are involved in redox or cell death-associated pathways. Leveraging the ability of tandem mass tagging mass spectrometry to provide quantitative data in an exploratory manner provides insight into the effect PB1 and other phosphine–borane compounds may have on the cysteine redoxome. Full article
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14 pages, 3746 KiB  
Article
Biologically Synthesized Silver Nanoparticles Efficiently Control Plant Pathogenic Bacteria-Erwinia carotovora and Ralstonia solanacearum
by Zainab Bibi, Mohammad Ali, Mohammed Abohashrh, Imtiaz Ahmad, Haji Khan, Murad Ali, Fazal Akbar, Nisar Ahmad, Arshad Iqbal, Farman Ullah, Zahid Ullah and Tahir Muhmood
Inorganics 2023, 11(7), 309; https://doi.org/10.3390/inorganics11070309 - 20 Jul 2023
Cited by 1 | Viewed by 1152
Abstract
Biogenic nanoparticles are considered effective alternatives to chemical pesticides for the management of pathogenic plant diseases. This study was focused on the synthesis of stable silver nanoparticles (AgNPs) to control challenging plant pathogenic bacteria in vitro and in planta. We synthesized AgNPs by [...] Read more.
Biogenic nanoparticles are considered effective alternatives to chemical pesticides for the management of pathogenic plant diseases. This study was focused on the synthesis of stable silver nanoparticles (AgNPs) to control challenging plant pathogenic bacteria in vitro and in planta. We synthesized AgNPs by reacting different proportions of silver nitrate and aqueous extract of Hedera nepalensis. The physicochemical properties of the synthesized AgNPs were determined by using various physical techniques. The TEM analysis revealed the AgNPs less than 50 nm in size and spherical shaped. For antibacterial assays, different concentrations (1000–15.62 µg/mL, 2-fold dilutions) of the extract-free AgNPs (Ef-AgNPs) or extract-mixed AgNPs (Em-AgNPs), and fruit extracts (FE) were used against plant pathogenic bacteria Erwinia carotovora subsp. carotovora, Erwinia carotovora subsp. atroseptica, and Ralstonia solanacearum. In the in vitro assays, we found significant inhibition of both bacterial species in response to maximum concentrations of AgNPs. Overall, Ef-AgNPs exhibited a higher percent inhibition of bacterial pathogens. In potato tubers assay, complete inhibition of Erwinia carotovora was observed, except for the lowest AgNPs concentration of 15.62 µg/mL. Similarly, exposure of tomato plants to Ralstonia solanacearum suspensions (OD600 = 0.2) in the soil-drenching experiment and post-exposure treatment with 1000 µg/mL and 125 µg/mL of AgNPs resulted in disease inhibition. This study provides the basis that biogenic nanoparticles prepared from Hedera nepalensis are one of the best substitutes to synthetic pesticide, having displayed better results to control the growth of phytopathogenic microbes. However, field studies need to be conducted in a controlled environment to scale up the current work and find out the efficacy of nanoparticles on a larger scale. Full article
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38 pages, 3801 KiB  
Review
Review on the Chemistry of [M(NH3)n](XO4)m (M = Transition Metal, X = Mn, Tc or Re, n = 1–6, m = 1–3) Ammine Complexes
by Raj Narain Mehrotra
Inorganics 2023, 11(7), 308; https://doi.org/10.3390/inorganics11070308 - 20 Jul 2023
Cited by 5 | Viewed by 1645
Abstract
The preparation of ammine complexes of transition metals having oxidizing anions such as permanganate and perrhenate ions is a great challenge due to possible reactions between ammonia and oxidizing anions during the synthesis of these materials. However, it has an important role in [...] Read more.
The preparation of ammine complexes of transition metals having oxidizing anions such as permanganate and perrhenate ions is a great challenge due to possible reactions between ammonia and oxidizing anions during the synthesis of these materials. However, it has an important role in both the development of new oxidants in organic chemistry and especially in the preparation of mixed-metal oxide catalyst precursors and metal alloys for their controlled temperature decomposition reactions. Therefore, in this paper, synthetic procedures to prepare ammonia complexes of transition metal permanganate, pertechnetate, and perrhenate (the VIIB group tetraoxometallates) salts have been comprehensively reviewed. The available data about these compounds’ structures and spectroscopic properties, including the presence of hydrogen bonds that act as redox reaction centers during thermal decomposition, are given and evaluated in detail. The nature of the thermal decomposition products has also been summarized. The available information about the role of the ammine complexes of transition metal permanganate salts in organic oxidation reactions, such as the oxidation of benzyl alcohols and regeneration of oxo-compounds from oximes and phenylhydrazones, including the kinetics of these processes, has also been collected. Their physical and chemical properties, including the thermal decomposition characteristics of known diammine (Ag(I), Cd, Zn, Cu(II), Ni(II)), triammine (Ag(I)), and simple or mixed ligand tetraammine (Cu(II), Zn, Cd, Ni(II), Co(II), Pt(II), Pd(II), Co(III)), Ru(III), pentaammine (Co(III), Cr(III), Rh(III) and Ir(III)), and hexaammine (Ni(II), Co(III), Cr(III)) complexes of transition metals with tetraoxometallate(VII) anions (M = Mn, Tc and Re), have been summarized. The preparation and properties of some special mixed ligand/anion/cation-containing complexes, such as [Ru(NH3)4(NO)(H2O)](ReO4)2, [Co(NH3)5(H2O)](ReO4)2, [Co(NH3)5X](MnO4)2 (X = Cl, Br), [Co(NH3)6]Cl2(MnO4), [Co(NH3)5ReO4]X2 (X = Cl, NO3, ClO4, ReO4), and K[Co(NH3)6]Cl2(MnO4)2, are also included. Full article
(This article belongs to the Special Issue Metal Complexes with N-donor Ligands)
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29 pages, 50063 KiB  
Review
The Tripodal Ligand’s 4f Complexes: Use in Molecular Magnetism
by Kira E. Vostrikova
Inorganics 2023, 11(7), 307; https://doi.org/10.3390/inorganics11070307 - 20 Jul 2023
Cited by 1 | Viewed by 1150
Abstract
A predictable type of coordination is a key property of tripodal ligands. Homo- and heteroleptic lanthanide complexes with tripodal ligands are a representative class of compounds. However, despite the fact that many of them are paramagnetic, their magnetic behavior is poorly studied. This [...] Read more.
A predictable type of coordination is a key property of tripodal ligands. Homo- and heteroleptic lanthanide complexes with tripodal ligands are a representative class of compounds. However, despite the fact that many of them are paramagnetic, their magnetic behavior is poorly studied. This is because their photophysical and catalytic properties are considered more attractive. In the present review, we try to summarize the available structural information and only a few examples of data on magnetic properties in order to draw some conclusions about the prospect of such ligands in the design of quantum molecular magnets involving lanthanide (Ln) ions. We would also like to catch the reader’s attention to the fact that, despite the consideration of a large part of the currently known Ln compounds with tripodal ligands, this review is not exhaustive. However, our goal is to draw the attention of magnetochemists and theoreticians to a whole niche of air-stable Ln complexes that is still out of their field of vision. Full article
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55 pages, 2623 KiB  
Review
How to Address Flame-Retardant Technology on Cotton Fabrics by Using Functional Inorganic Sol–Gel Precursors and Nanofillers: Flammability Insights, Research Advances, and Sustainability Challenges
by Valentina Trovato, Silvia Sfameni, Rim Ben Debabis, Giulia Rando, Giuseppe Rosace, Giulio Malucelli and Maria Rosaria Plutino
Inorganics 2023, 11(7), 306; https://doi.org/10.3390/inorganics11070306 - 18 Jul 2023
Cited by 2 | Viewed by 2991
Abstract
Over the past decade, inorganic fillers and sol–gel-based flame-retardant technologies for textile treatments have gained increasing research interest as useful alternatives to hazardous chemicals previously employed in textile coating and finishing. This review presents the current state of the art of inorganic flame-retardant [...] Read more.
Over the past decade, inorganic fillers and sol–gel-based flame-retardant technologies for textile treatments have gained increasing research interest as useful alternatives to hazardous chemicals previously employed in textile coating and finishing. This review presents the current state of the art of inorganic flame-retardant technology for cotton fabrics to scientists and researchers. Combustion mechanism and flammability, as well as the thermal behavior of neat cotton samples, are first introduced. The main section is focused on assessing the effect of inorganic and sol–gel-based systems on the final flame-retardant properties of cotton fabrics, emphasizing their fire safety characteristics. When compared to organic flame-retardant solutions, inorganic functional fillers have been shown to be more environmentally friendly and pollution-free since they do not emit compounds that are hazardous to ecosystems and humans when burned. Finally, some perspectives and recent advanced research addressing the potential synergism derived from the use of inorganic flame retardants with other environmentally suitable molecules toward a sustainable flame-retardant technological approach are reviewed. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Inorganic Materials)
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10 pages, 2884 KiB  
Article
Two Birds with One Stone: Ammonium-Induced Carbon Nanotube Structure and Low-Crystalline Cobalt Nanoparticles Enabling High Performance of Lithium-Sulfur Batteries
by Qi Tan, Hongliang Liu, Guozhu Liang, Kaigui Jiang, Hangxuan Xie, Weijie Si, Jiajv Lin and Xiongwu Kang
Inorganics 2023, 11(7), 305; https://doi.org/10.3390/inorganics11070305 - 18 Jul 2023
Cited by 2 | Viewed by 1071
Abstract
The electrochemical performance of lithium–sulfur batteries (LiSBs) has been hampered by the slow redox kinetics and shuttle effect of lithium polysulfides (LiPSs), which require the rational design and synthesis of highly active electrocatalysts towards this reaction. Herein, worm-like N-doped porous carbon nanotube-supported low-crystalline [...] Read more.
The electrochemical performance of lithium–sulfur batteries (LiSBs) has been hampered by the slow redox kinetics and shuttle effect of lithium polysulfides (LiPSs), which require the rational design and synthesis of highly active electrocatalysts towards this reaction. Herein, worm-like N-doped porous carbon nanotube-supported low-crystalline Co nanoparticles (a-Co-NC@C) were derived from binary Zn–Co ZIF via a two-step thermal annealing method. Initial thermal annealing 950 °C in Ar + H2 atmosphere results in the carbonization of binary Zn–Co ZIF and the formation of high crystalline Co nanoparticles. Thermal annealing in ammonia atmosphere at 350 °C not only results in the reduced crystallinity of cobalt nanoparticles; it also promotes the growth of highly graphitized and heavily N-doped intertwined carbon nanotubes. The enlarged porous carbon nanotube structure offers accommodation for sulfur content, while the doped carbon and Co nanoparticles with reduced crystallinity facilitate the redox kinetics of LiPSs, improving the cycling stability, rate performance and capacity of LiSBs batteries. As a result, the a-Co-NC@C cathode displays a specific capacity of 559 mAh g−1 after 500 cycles at 1 C, and a specific capacity of 572 mAh g−1 at 3 C. It delivers a specific capacity of 579 mAh g−1 at high sulfur loading of a 2.55 mg cm−2 at 1 C after 400 cycles. This work highlights the importance of phase engineering of carbon matrix and transition metal nanoparticles in electrochemical performance of Li-S batteries. Full article
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15 pages, 3724 KiB  
Article
Transannular Selenocyclofunctionalization of 1,5-cyclooctadiene: The Antioxidant Properties of 9-selenabicyclo[3.3.1]nonane Derivatives and the Discovery of Increasing Both GPx and GR Activities
by Maxim V. Musalov, Irina S. Kapustina, Ekaterina V. Spiridonova, Natalya V. Ozolina, Svetlana V. Amosova, Tatyana N. Borodina and Vladimir A. Potapov
Inorganics 2023, 11(7), 304; https://doi.org/10.3390/inorganics11070304 - 15 Jul 2023
Cited by 3 | Viewed by 1085
Abstract
Oxidative stress is the cause of various pathologies and disorders of cellular functions. Substances that reduce the pathological effect of oxidative stress on homeostasis include organoselenium compounds of natural and synthetic origin. Depending on the structure, organoselenium compounds can exhibit different biological activities, [...] Read more.
Oxidative stress is the cause of various pathologies and disorders of cellular functions. Substances that reduce the pathological effect of oxidative stress on homeostasis include organoselenium compounds of natural and synthetic origin. Depending on the structure, organoselenium compounds can exhibit different biological activities, for example, reducing oxidative stress, participating in the regulation of signaling systems, influencing the synthesis of cytokines, etc. This makes them promising products for the development of new means of metabolic correction and drugs with enzyme-like activity. This study is aimed at developing an effective method for the synthesis of functional organoselenium compounds and studying their antioxidant effect in vivo under stress conditions. A one-pot catalyst-free method of transannular addition-functionalization of cis,cis-1,5-cyclooctadiene with selenium dihalides in the presence of nucleophiles was developed. For the first time, the antioxidant activity of functionalized 9-selenabicyclo[3.3.1]nonanes was studied in vivo. Quantitative characteristics of the effect on the level of lipid peroxidation and the activity of glutathione peroxidase and glutathione reductase under stress conditions were obtained. The effect of substituents in the selenium-containing scaffold on the biological activity of the compounds was studied. The water-soluble 9-selenabicyclo[3.3.1]nonane derivatives, containing hydroxyl and 2-hydroxyethoxy groups, which increased the activity of both glutathione peroxidase and glutathione reductase, were discovered. Full article
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15 pages, 2552 KiB  
Article
Dependence of Ge/Si Avalanche Photodiode Performance on the Thickness and Doping Concentration of the Multiplication and Absorption Layers
by Hazem Deeb, Kristina Khomyakova, Andrey Kokhanenko, Rahaf Douhan and Kirill Lozovoy
Inorganics 2023, 11(7), 303; https://doi.org/10.3390/inorganics11070303 - 15 Jul 2023
Cited by 1 | Viewed by 1847
Abstract
In this article, the performance and design considerations of the planar structure of germanium on silicon avalanche photodiodes are presented. The dependences of the breakdown voltage, gain, bandwidth, responsivity, and quantum efficiency on the reverse bias voltage for different doping concentrations and thicknesses [...] Read more.
In this article, the performance and design considerations of the planar structure of germanium on silicon avalanche photodiodes are presented. The dependences of the breakdown voltage, gain, bandwidth, responsivity, and quantum efficiency on the reverse bias voltage for different doping concentrations and thicknesses of the absorption and multiplication layers of germanium on the silicon avalanche photodiode were simulated and analyzed. The study revealed that the gain of the avalanche photodiode is directly proportional to the thickness of the multiplication layer. However, a thicker multiplication layer was also associated with a higher breakdown voltage. The bandwidth of the device, on the other hand, was inversely proportional to the product of the absorption layer thickness and the carrier transit time. A thinner absorption layer offers a higher bandwidth, but it may compromise responsivity and quantum efficiency. In this study, the dependence of the photodetectors’ operating characteristics on the doping concentration used for the multiplication and absorption layers is revealed for the first time. Full article
(This article belongs to the Special Issue Advanced Inorganic Semiconductor Materials)
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33 pages, 8416 KiB  
Review
Homogeneous Metal-Catalyzed Hydrogenation of CO2 Derivatives: Towards Indirect Conversion of CO2 to Methanol
by Tolganay Andizhanova, Aziza Adilkhanova and Andrey Y. Khalimon
Inorganics 2023, 11(7), 302; https://doi.org/10.3390/inorganics11070302 - 15 Jul 2023
Cited by 1 | Viewed by 1862
Abstract
The increase in anthropogenic CO2 concentrations and associated environmental issues have demanded the development of technologies for CO2 utilization. Among various potential solutions to decrease CO2 emissions and achieve carbon neutrality, the recycling of post-combustion CO2 into value-added chemicals [...] Read more.
The increase in anthropogenic CO2 concentrations and associated environmental issues have demanded the development of technologies for CO2 utilization. Among various potential solutions to decrease CO2 emissions and achieve carbon neutrality, the recycling of post-combustion CO2 into value-added chemicals and fuels is considered one of the most economically attractive processes. In this regard, due to its large global demand and versatile applications in the chemical and energy sectors, methanol serves as the most appealing target for the chemical utilization of CO2. However, direct hydrogenation of CO2 to MeOH has proved challenging due to selectivity issues and high energy input, mainly dependent on CO2-emitting fossil energy sources. To address these challenges, an alternative indirect CO2-to-MeOH methodology has been proposed, which involves the hydrogenation of CO2 via the intermediate formation of well-known CO2 derivatives, such as formates, carbonates, formamides, carbamates, and urea derivatives. Homogeneous transition metal catalysts have been at the center of this research avenue, potentially allowing for more selective and low-temperature alternative routes from CO2 to MeOH. This review aims to highlight the advances and challenges in homogeneous transition metal-catalyzed hydrogenation of major CO2 derivatives to MeOH. Special attention is paid to the mechanisms of such transformations. Full article
(This article belongs to the Section Organometallic Chemistry)
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11 pages, 3962 KiB  
Article
Strain Modulation of Electronic Properties in Monolayer SnP2S6 and GeP2S6
by Junlei Zhou, Yuzhou Gu, Yue-E Xie, Fen Qiao, Jiaren Yuan, Jingjing He, Sake Wang, Yangsheng Li and Yangbo Zhou
Inorganics 2023, 11(7), 301; https://doi.org/10.3390/inorganics11070301 - 15 Jul 2023
Cited by 2 | Viewed by 1146
Abstract
In recent years, two-dimensional (2D) materials have attracted significant attention due to their distinctive properties, including exceptional mechanical flexibility and tunable electronic properties. Via the first-principles calculation, we investigate the effect of strain on the electronic properties of monolayer SnP2S6 [...] Read more.
In recent years, two-dimensional (2D) materials have attracted significant attention due to their distinctive properties, including exceptional mechanical flexibility and tunable electronic properties. Via the first-principles calculation, we investigate the effect of strain on the electronic properties of monolayer SnP2S6 and GeP2S6. We find that monolayer SnP2S6 is an indirect bandgap semiconductor, while monolayer GeP2S6 is a direct bandgap semiconductor. Notably, under uniform biaxial strains, SnP2S6 undergoes an indirect-to-direct bandgap transition at 4.0% biaxial compressive strains, while GeP2S6 exhibits a direct-to-indirect transition at 2.0% biaxial tensile strain. The changes in the conduction band edge can be attributed to the high-symmetry point Γ being more sensitive to strain than K. Thus, the relocation of the conduction band and valence band edges in monolayer SnP2S6 and GeP2S6 induces a direct-to-indirect and indirect-to-direct bandgap transition, respectively. Consequently, the strain is an effective band engineering scheme which is crucial for the design and development of next-generation nanoelectronic and optoelectronic devices. Full article
(This article belongs to the Special Issue Advanced Inorganic Semiconductor Materials)
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10 pages, 2829 KiB  
Article
FeNi Confined in N-Doped Carbon as a Highly Efficient Bi-Functional Catalyst for Rechargeable Zn–Air Batteries
by Lei Duan, Zhili Ren, Xiaoling Chen, Ding Zhang and Shoudong Xu
Inorganics 2023, 11(7), 300; https://doi.org/10.3390/inorganics11070300 - 14 Jul 2023
Viewed by 1062
Abstract
Rechargeable zinc–air batteries (RZABs) are basically dependent on both affordable and long-lasting bifunctional electrocatalysts. A non-precious metal catalyst, a FeNi nanoalloy catalyst (FeNi@NC) with an extremely low metal consumption (0.06 mmol), has been successfully synthesized. It shows a high half-wave potential of 0.845 [...] Read more.
Rechargeable zinc–air batteries (RZABs) are basically dependent on both affordable and long-lasting bifunctional electrocatalysts. A non-precious metal catalyst, a FeNi nanoalloy catalyst (FeNi@NC) with an extremely low metal consumption (0.06 mmol), has been successfully synthesized. It shows a high half-wave potential of 0.845 V vs. RHE for ORR and a low overpotential of 318 mV for OER at 10 mA cm−2, favoring a maximum power density of 116 mW cm−2 for the constructed RZABs. The voltage plateau is reserved even after 167 h of cell operation. The synergistic effect between the nano-sized FeNi alloy and nitrogen-doped carbon with abundant N sites mainly contributes to the electrocatalytic activity. This research can provide some useful guidelines for the development of economic and efficient bifunctional catalysts for RZABs. Full article
(This article belongs to the Special Issue Inorganic Materials for Lithium Sulfur Batteries and Electrocatalysis)
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16 pages, 5487 KiB  
Article
Processing, Phase Stability, and Conductivity of Multication-Doped Ceria
by Elizabeth Gager and Juan C. Nino
Inorganics 2023, 11(7), 299; https://doi.org/10.3390/inorganics11070299 - 14 Jul 2023
Cited by 2 | Viewed by 1149
Abstract
Multicomponent doping of ceria with four cations is used as a preliminary investigation into the ionic conductivity of high-entropy-doped ceria systems. Different compositions of Ce1-x(Ndx/4Prx/4Smx/4Gdx/4)O2-δ (x = 0.05, 0.10, 0.15, and 0.20) [...] Read more.
Multicomponent doping of ceria with four cations is used as a preliminary investigation into the ionic conductivity of high-entropy-doped ceria systems. Different compositions of Ce1-x(Ndx/4Prx/4Smx/4Gdx/4)O2-δ (x = 0.05, 0.10, 0.15, and 0.20) are synthesized using the oxalate co-precipitation method yielding single-phase oxalate precursors. X-ray diffraction, Raman spectroscopy, and Fourier-transform infrared spectroscopy are used to characterize the precipitated oxalates. Simultaneous thermal gravimetric analysis and differential scanning calorimetry reveal a two-step decomposition of the oxalates into the doped oxide. The ionic conductivity of the samples is measured from 250 °C to 600 °C using electrochemical impedance spectroscopy. All samples exhibit similar grain conductivity values at 600 °C, comparable to singly doped samples. However, an increase in total conductivity is observed with an increase in doping concentration up to 15% followed by a decrease beyond this concentration. These findings suggest that multicomponent doping may not significantly enhance the grain conductivity of doped ceria beyond conventional single and co-doped compositions but can modulate the grain boundary conductivity and thus the total conductivity of ceria ceramics. Full article
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18 pages, 6285 KiB  
Article
The Mechanical Properties of Geopolymers from Different Raw Materials and the Effect of Recycled Gypsum
by Henna Korhonen, Juha Timonen, Sari Suvanto, Pipsa Hirva, Kirsi Mononen and Sirpa Jääskeläinen
Inorganics 2023, 11(7), 298; https://doi.org/10.3390/inorganics11070298 - 14 Jul 2023
Viewed by 1189
Abstract
Geopolymers are amorphous inorganic polymers that are mainly used in the construction industry as an environmentally friendly alternative to ordinary cement. This study compared selected mechanical properties (setting time, shrinkage, strength) of geopolymer specimens made from different main raw materials, mainly at room [...] Read more.
Geopolymers are amorphous inorganic polymers that are mainly used in the construction industry as an environmentally friendly alternative to ordinary cement. This study compared selected mechanical properties (setting time, shrinkage, strength) of geopolymer specimens made from different main raw materials, mainly at room temperature, and investigated the effects of recycled gypsum on these. A structural analysis of the specimens was conducted with XRD and SEM. Also, the leaching of aluminium, silicon, and calcium from the specimens was investigated. According to this study, raw materials have a significant impact on the properties of geopolymers. Recycled gypsum affected the setting time of the geopolymers, but the effect was not the same for all specimens. It increased the setting time of specimens made from calcium-rich raw materials, for example, and the ground-granulated blast furnace slag specimens hardened as fast as ordinary Portland cement (about 300 min), but the addition of gypsum decreased it to 1300 min. Gypsum-containing specimens, based on Ca-deficient metakaolin or fly ash, hardened even faster than OPC, in 100–150 min. Recycled gypsum significantly reduced the plastic shrinkage of most of the 28 d specimens to lower values than those achieved for OPC (0.07%). The only exceptions were the fly-ash-based specimens. However, gypsum had no effect on the drying shrinkage, which accounted for a larger proportion of the total shrinkage in most specimens. Therefore, it had no significant effect on the total shrinkage of the geopolymer specimens. The reducing effect of gypsum on the plastic shrinkage of geopolymers was attributed to ettringite, which was observed in all gypsum-containing specimens analysed with XRD. In this study, recycled gypsum decreased the compressive strength of the specimens, which could be prevented by using a finer gypsum powder. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Inorganic Materials)
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9 pages, 2237 KiB  
Article
Hierarchical ZSM-5 Zeolite Synthesized Only with Simple Organic Templates
by Ying Zhao, Yuanchen Li, Peng Cheng and Hongdan Zhang
Inorganics 2023, 11(7), 297; https://doi.org/10.3390/inorganics11070297 - 14 Jul 2023
Cited by 2 | Viewed by 1439
Abstract
Hierarchical zeolites have attracted more and more attention due to their excellent diffusion and mass transfer performance. However, synthesis of most hierarchical zeolites requires long-chain organic templates, which could increase preparation cost. Here, hierarchical ZSM-5 zeolites were successfully prepared with simple organic templates [...] Read more.
Hierarchical zeolites have attracted more and more attention due to their excellent diffusion and mass transfer performance. However, synthesis of most hierarchical zeolites requires long-chain organic templates, which could increase preparation cost. Here, hierarchical ZSM-5 zeolites were successfully prepared with simple organic templates (triethylenetetramine) in a rotating oven. Besides hierarchical structure, the crystal size of ZSM-5 also decreased when they were synthesized under dynamic hydrothermal conditions. The samples were analyzed using various physicochemical characterizations, such as X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), Fourier transform infrared spectra (FT-IR), temperature-programmed desorption of ammonia (NH3-TPD) and N2 adsorption–desorption. The hierarchical ZSM-5 zeolites synthesized in a rotating oven presented better catalytic activity and stability in iso-butane cracking reaction than those synthesized under conventional static hydrothermal conditions. Full article
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22 pages, 5134 KiB  
Review
In Situ Techniques for Characterization of Layered Double Hydroxide-Based Oxygen Evolution Catalysts
by Andraž Mavrič and Matjaž Valant
Inorganics 2023, 11(7), 296; https://doi.org/10.3390/inorganics11070296 - 13 Jul 2023
Viewed by 1673
Abstract
Functional layered double hydroxide (LDH) usually contains different cationic substitutes to increase the activity of the oxygen evolution reaction (OER). The intrinsic OER activity of LDH materials is connected with the chemical composition and dispersion of metal cations substitutions in the matrix phase. [...] Read more.
Functional layered double hydroxide (LDH) usually contains different cationic substitutes to increase the activity of the oxygen evolution reaction (OER). The intrinsic OER activity of LDH materials is connected with the chemical composition and dispersion of metal cations substitutions in the matrix phase. The potential induced phase transitions, in particular hydroxide-to-oxyhydroxide transitions, are a predisposition for the high OER activity of LDH materials and can be followed by coupling the electrochemical experiments with spectroscopic techniques. The understanding of LDH catalysts under electrochemical conditions also allows an understanding of the behavior of OER catalysts based on transition metals, metal-chalcogenides, -pnictides, -carbides, and metal–organic frameworks. The surfaces of those materials are intrinsically poor OER catalysts. However, they act as precursors to catalysts, which are oxidized into a metal (oxy)hydroxide. This review summarizes the use of in situ techniques for the characterization of LDH-based OER electrocatalysts and presents the influence of these techniques on the understanding of potential induced phase transitions, identification of active sites, and reaction mechanisms. Full article
(This article belongs to the Special Issue Layered Double Hydroxides for Catalytic Applications)
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20 pages, 5484 KiB  
Article
Complexation of Boron and Aluminum with a Bidentate Hydroxy-BN-naphthalene Ligand
by Yannik Appiarius, Pim Puylaert, Julius Werthschütz, Tim Neudecker and Anne Staubitz
Inorganics 2023, 11(7), 295; https://doi.org/10.3390/inorganics11070295 - 12 Jul 2023
Cited by 1 | Viewed by 1499
Abstract
The isoelectronic relationship of 1,2-azaborinine (B=N structural motif) and benzene (C=C) is well documented. Upon deprotonation of the former, the anionic 1,2-azaboratabenzene is obtained, which is isosteric with pyridine (C=N) and has a similar capability as an aromatic N-donor. We present the [...] Read more.
The isoelectronic relationship of 1,2-azaborinine (B=N structural motif) and benzene (C=C) is well documented. Upon deprotonation of the former, the anionic 1,2-azaboratabenzene is obtained, which is isosteric with pyridine (C=N) and has a similar capability as an aromatic N-donor. We present the complexation of boron and aluminum precursors with a κ2-N,O-donating 8-hydroxy-BN-naphthalene ligand (H2(BQ), 1). Six chelate complexes with 1:1 and 2:1 stoichiometries were isolated and characterized by X-ray diffraction analysis and NMR spectroscopy. Comparing the isosteric dimethylaluminum complexes of H2(BQ) and an 8-hydroxyquinoline (HQ’, 2) as a reference allowed us to quantify the influence of a formal substitution of carbon by boron on the structure and the electronic properties: While the structural parameters of the ligands were similar, the electropositive boron atom affected the electron density distributions within the complexes substantially. As the consequence, the Al–N bond was significantly shortened, and the aluminum atom showed a different coordination geometry than in the quinoline analog. Moreover, strong hypsochromic shifts of both the absorption and the emission were observed. The results highlight that the differences between CN and BN polyaromatic complexes are more distinct than between equally charged BN and CC congeners. Full article
(This article belongs to the Special Issue Boron Chemistry: Fundamentals and Applications)
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22 pages, 3297 KiB  
Review
Nanomaterials Used in the Preparation of Personal Protective Equipment (PPE) in the Fight against SARS-CoV-2
by Pierantonio De Luca, Janos B.Nagy and Anastasia Macario
Inorganics 2023, 11(7), 294; https://doi.org/10.3390/inorganics11070294 - 12 Jul 2023
Cited by 1 | Viewed by 1673
Abstract
Following the well-known pandemic, declared on 30 January 2020 by the World Health Organization, the request for new global strategies for the prevention and mitigation of the spread of the infection has come to the attention of the scientific community. Nanotechnology has often [...] Read more.
Following the well-known pandemic, declared on 30 January 2020 by the World Health Organization, the request for new global strategies for the prevention and mitigation of the spread of the infection has come to the attention of the scientific community. Nanotechnology has often managed to provide solutions, effective responses, and valid strategies to support the fight against SARS-CoV-2. This work reports a collection of information on nanomaterials that have been used to counter the spread of the SARS-CoV-2 virus. In particular, the objective of this work was to illustrate the strategies that have made it possible to use the particular properties of nanomaterials, for the production of personal protective equipment (DIP) for the defense against the SARS-CoV-2 virus. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Inorganic Materials)
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20 pages, 6161 KiB  
Article
Benzimidazole-Based NHC Metal Complexes as Anticancer Drug Candidates: Gold(I) vs. Platinum(II)
by Paul Kapitza, Patricia Grabher, Amelie Scherfler, Klaus Wurst, Brigitte Kircher, Ronald Gust and Hristo P. Varbanov
Inorganics 2023, 11(7), 293; https://doi.org/10.3390/inorganics11070293 - 11 Jul 2023
Cited by 3 | Viewed by 1903
Abstract
Herein, we present a comparative study on the chemistry and biological activity of N-heterocyclic carbene (NHC)Pt(II)/Au(I) complexes. Accordingly, representative compounds of the cis/trans- [PtL2X2] (X = Cl (5, 6) or I (7 [...] Read more.
Herein, we present a comparative study on the chemistry and biological activity of N-heterocyclic carbene (NHC)Pt(II)/Au(I) complexes. Accordingly, representative compounds of the cis/trans- [PtL2X2] (X = Cl (5, 6) or I (7, 8)), [PtL3Cl]+ (9), [AuLX] (X = Cl (10) or I (11)), and [AuL2]+ (12) type, where L is 1,3-diethylbenzimidazol-2-ylidene, were synthesized and characterized in detail to elucidate the role of the metal center on their physicochemical and biological properties. The stability of the complexes in the presence of cell culture medium and their reactivity toward relevant biomolecules were investigated by RP-HPLC. In addition, their effects on plasmid DNA and in vitro cytotoxicity in ovarian cancer cells and non-malignant fibroblasts were evaluated. Cationic [AuL2]+ and [PtL3X]+ species displayed the highest cytotoxicity and stability in cell culture medium in the series. They exhibited IC50 values lower than the established metallodrugs cisplatin and auranofin in both wild-type and cisplatin-resistant ovarian cancer cells, being able to circumvent cisplatin resistance. Finally, Pt(II)–NHC complexes form 5′-guanosine monophosphate adducts under physiologically relevant conditions and interact with plasmid DNA in contrast to their Au(I) analogs, corroborating their distinct modes of action. Full article
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8 pages, 2675 KiB  
Communication
Green Synthesis of MIL-88B(Cr) with the Co-Modulator of Nitric Acid and Acetic Acid
by Fuzhi Li, Songfan Tang, Mingmin Li, Pengcheng Xiao, Mingliang Luo and Tian Zhao
Inorganics 2023, 11(7), 292; https://doi.org/10.3390/inorganics11070292 - 11 Jul 2023
Cited by 1 | Viewed by 1279
Abstract
MIL-88B(Cr) is a prototypical flexible chromium-based metal-organic framework (MOF), which possesses extremely strong water/thermal stability and excellent “swelling/breathing” ability. However, in previous studies, there have been very few reports on MIL-88B(Cr) due to unclear synthesis details. Here, we found that the pure MIL-88B(Cr) [...] Read more.
MIL-88B(Cr) is a prototypical flexible chromium-based metal-organic framework (MOF), which possesses extremely strong water/thermal stability and excellent “swelling/breathing” ability. However, in previous studies, there have been very few reports on MIL-88B(Cr) due to unclear synthesis details. Here, we found that the pure MIL-88B(Cr) can be facile synthesized through a hydrothermal method with the co-use of nitric acid and acetic acid (molar ratio = 1:15). The obtained MIL-88B(Cr) was sufficiently characterized by diverse techniques to assure its high-level quality. This work emphasizes a future valuable approach to expanding the production of flexible Cr-based MOF. Full article
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17 pages, 8996 KiB  
Article
Synthesis, Luminescence and Energy Transfer Properties of Ce3+/Mn2+ Co-Doped Calcium Carbodiimide Phosphors
by Erwan Leysour de Rohello, Yan Suffren, Francis Gouttefangeas, Odile Merdrignac-Conanec, Olivier Guillou and François Cheviré
Inorganics 2023, 11(7), 291; https://doi.org/10.3390/inorganics11070291 - 7 Jul 2023
Viewed by 1079
Abstract
Ce3+-doped and Ce3+/Mn2+ co-doped calcium carbodiimide (CaCN2) phosphors were synthesized from doped calcium carbonate and carbon nitride by a solid-state reaction at 700 °C under flowing NH3 using a very short reaction time (1 h). [...] Read more.
Ce3+-doped and Ce3+/Mn2+ co-doped calcium carbodiimide (CaCN2) phosphors were synthesized from doped calcium carbonate and carbon nitride by a solid-state reaction at 700 °C under flowing NH3 using a very short reaction time (1 h). The samples were characterized by powder X-ray diffraction, scanning electron microscopy and their diffuse reflectance and luminescence properties were investigated. Single-doped CaCN2:Ce3+ exhibits a blue emission under near-ultraviolet activation (386 nm) corresponding to the 5d12F5/2 and 5d12F7/2 transitions of Ce3+. Maximum emission is obtained at temperatures lower than 150 K and then progressively decreases up to 387 K, with an 80% drop in the emission at room temperature. Efficient energy transfers from Ce3+ to Mn2+ via a non-radiative dipole–dipole mechanism are evidenced for the co-doped samples, leading to various colored phosphors under near-ultraviolet activation (386 nm). The emission color of the obtained phosphors can be modulated from blue to red through a shade of white depending on the sensitizer/activator ratio. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Inorganic Solid State Chemistry)
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10 pages, 2212 KiB  
Article
Metal Hydride Hydrogen Storage (Compression) Units Operating at Near-Atmospheric Pressure of the Feed H2
by Boris Tarasov, Artem Arbuzov, Sergey Mozhzhukhin, Aleksey Volodin, Pavel Fursikov, Moegamat Wafeeq Davids, Joshua Adeniran and Mykhaylo Lototskyy
Inorganics 2023, 11(7), 290; https://doi.org/10.3390/inorganics11070290 - 6 Jul 2023
Cited by 1 | Viewed by 1338
Abstract
Metal hydride (MH) hydrogen storage and compression systems with near-atmospheric H2 suction pressure are necessary for the utilization of the low-pressure H2 produced by solid oxide electrolyzers or released as a byproduct of chemical industries. Such systems should provide reasonably high [...] Read more.
Metal hydride (MH) hydrogen storage and compression systems with near-atmospheric H2 suction pressure are necessary for the utilization of the low-pressure H2 produced by solid oxide electrolyzers or released as a byproduct of chemical industries. Such systems should provide reasonably high productivity in the modes of both charge (H2 absorption at PL ≤ 1 atm) and discharge (H2 desorption at PH = 2–5 atm), which implies the provision of H2 equilibrium pressures Peq < PL at the available cooling temperature (TL = 15–20 °C) and, at the same time, Peq > PH when heated to TH = 90–150 °C. This work presents results of the development of such systems based on AB5-type intermetallics characterized by Peq of 0.1–0.3 atm and 3–8 atm for H2 absorption at TL = 15 °C and H2 desorption at TH = 100 °C, respectively. The MH powders mixed with 1 wt.% of Ni-doped graphene-like material or expanded natural graphite for the improvement of H2 charge dynamics were loaded in a cylindrical container equipped with internal and external heat exchangers. The developed units with a capacity of about 1 Nm3 H2 were shown to exhibit H2 flow rates above 10 NL/min during H2 charge at ≤1 atm when cooled to ≤20 °C with cold water and H2 release at a pressure above 2 and 5 atm when heated to 90 and 120 °C with hot water and steam, respectively. Full article
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18 pages, 11018 KiB  
Review
Recent Advances in Anode Materials for Sodium-Ion Batteries
by Xue Bai, Nannan Wu, Gengchen Yu and Tao Li
Inorganics 2023, 11(7), 289; https://doi.org/10.3390/inorganics11070289 - 6 Jul 2023
Cited by 8 | Viewed by 5354
Abstract
Although lithium-ion battery (LIB) technology has prevailed for years, the growing pressure and increased cost of lithium sources urge the rapid development of other promising energy storage devices. As a low-cost alternative, sodium-ion batteries (SIBs) with similar properties of electrochemical reaction have caught [...] Read more.
Although lithium-ion battery (LIB) technology has prevailed for years, the growing pressure and increased cost of lithium sources urge the rapid development of other promising energy storage devices. As a low-cost alternative, sodium-ion batteries (SIBs) with similar properties of electrochemical reaction have caught researchers’ attention. Nevertheless, great challenges of inferior reversible capacity and poor lifespan induced by the bigger ionic radius of sodium ions still exist. To solve these problems, improvements to anode materials prove to be an effective way. Herein, the latest research on promising anodes in SIBs is summarized, and the further prospects are also illustrated. Full article
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14 pages, 6730 KiB  
Article
Phase Formation of Co and Cr Co-Doped Bismuth Niobate with Pyrochlore Structure
by Nadezhda A. Zhuk, Ksenia A. Badanina, Roman I. Korolev, Boris A. Makeev, Maria G. Krzhizhanovskaya and Vladislav V. Kharton
Inorganics 2023, 11(7), 288; https://doi.org/10.3390/inorganics11070288 - 3 Jul 2023
Viewed by 954
Abstract
The formation mechanisms of pyrochlore-type Bi2Co1/2Cr1/2Nb2O9+Δ (space group Fd-3m, a = 10.4838(8) Å), in the temperature range from 400 to 1050 °C were studied by employing X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy. [...] Read more.
The formation mechanisms of pyrochlore-type Bi2Co1/2Cr1/2Nb2O9+Δ (space group Fd-3m, a = 10.4838(8) Å), in the temperature range from 400 to 1050 °C were studied by employing X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy. An extensive reaction between the binary metal oxides was found to begin at temperatures above 550 °C, following the transition of monoclinic α-Bi2O3 into a tetragonal β-Bi2O3 polymorph. The synthesis process occurs in several stages when Bi-rich intermediate products (Bi6CrO12, Bi6Cr2O15, and Bi5Nb3O15) transform into bismuth-depleted BiNbO4 and a chromium–cobalt spinel is formed. The formation of a single pyrochlore phase occurs at the final reaction stage at 1050 °C via the doping of bismuth ortho-niobate, BiNbO4, by the transition metal cations. The observed mechanism is essentially similar to the mechanism of tantalate-based phases except for the formation of Bi5Nb3O15 at the intermediate reaction stages. Full article
(This article belongs to the Section Inorganic Solid-State Chemistry)
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37 pages, 14349 KiB  
Review
Elemental Selenium in the Synthesis of Selenaheterocycles
by Alexander V. Martynov
Inorganics 2023, 11(7), 287; https://doi.org/10.3390/inorganics11070287 - 2 Jul 2023
Cited by 2 | Viewed by 1891
Abstract
An overview of the known methods of introducing selenium under the action of elemental selenium into the structures of various saturated, unsaturated, and heteroaromatic selenacycles containing C–Se, N–Se, B–Se, Ge–Se and P–Se bonds is presented. These methods include metal, iodine, bromine or chlorine [...] Read more.
An overview of the known methods of introducing selenium under the action of elemental selenium into the structures of various saturated, unsaturated, and heteroaromatic selenacycles containing C–Se, N–Se, B–Se, Ge–Se and P–Se bonds is presented. These methods include metal, iodine, bromine or chlorine exchange for selenium and the direct cyclization of 1-(2-bromoaryl)benzimidazoles, polyunsaturated hydrocarbons, acetylenes, propargylic amines, 3-halogenaryl amides, aryl amides, diazo-compounds, 2-aminoacetophenone, and the annulation of ethynyl arenes. Three- and four-component reactions utilizing elemental selenium as one of the components and leading to selenium-containing heterocycles are presented as well. Full article
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10 pages, 2294 KiB  
Article
Unveiling the Thermoelectric Performances of Zn1−xFexSe Nanoparticles Prepared by the Hydrothermal Method
by Muhammad Isram, Valeria Demontis, Riccardo Magrin Maffei, Najaf Abbas Khan, Alessandro di Bona, Stefania Benedetti, Nasir Amin, Khalid Mahmood and Francesco Rossella
Inorganics 2023, 11(7), 286; https://doi.org/10.3390/inorganics11070286 - 2 Jul 2023
Viewed by 1342
Abstract
Fe2+-doped ZnSe nanoparticles, with varying concentrations of Fe2+ dopants, were prepared by the hydrothermal method and investigated using a multi-technique approach exploiting scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy, as well as measurement of the electrical transport [...] Read more.
Fe2+-doped ZnSe nanoparticles, with varying concentrations of Fe2+ dopants, were prepared by the hydrothermal method and investigated using a multi-technique approach exploiting scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy, as well as measurement of the electrical transport properties and Seebeck coefficient (S). The doped nanoparticles appeared as variable-sized agglomerates on nanocrystallites upon SEM investigation for any doping level. Combined XRD and Raman analyses revealed the occurrence of a cubic structure in the investigated samples. Electric and thermoelectric (TE) transport investigations showed an increase in TE performance with an increase in Fe atom concentrations, which resulted in an enhancement of the power factors from 13 µWm−1K−2 to 120 µWm−1K−2 at room temperature. The results were also dependent on the operating temperature. The maximum power factor of 9 × 10−3 Wm−1K−2 was achieved at 150 °C for the highest explored doping value. The possible applications of these findings were discussed. Full article
(This article belongs to the Special Issue Advances of Thermoelectric Materials)
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11 pages, 6271 KiB  
Article
XPS and NEXAFS Studies of Zn-Doped Bismuth Iron Tantalate Pyrochlore
by Sergey V. Nekipelov, Victor N. Sivkov, Danil V. Sivkov, Alexey M. Lebedev, Ratibor G. Chumakov, Aleksandra V. Koroleva, Boris A. Makeev and Nadezhda A. Zhuk
Inorganics 2023, 11(7), 285; https://doi.org/10.3390/inorganics11070285 - 2 Jul 2023
Cited by 1 | Viewed by 1096
Abstract
The effect of Zn-doping on the phase composition and optical properties of the Bi2ZnxFe1-xTa2O9.5-Δ (x = 0.3, 0.5, 0.7) was studied. XRD data showed that the samples crystallize in the structural type of pyrochlore [...] Read more.
The effect of Zn-doping on the phase composition and optical properties of the Bi2ZnxFe1-xTa2O9.5-Δ (x = 0.3, 0.5, 0.7) was studied. XRD data showed that the samples crystallize in the structural type of pyrochlore (sp. gr.Fd-3m). For all the samples, an admixture of bismuth orthotantalate β-BiTaO4 triclinic modification up to 22.5 wt.% is observed. The content of β-BiTaO4 increases with zinc doping. The unit cell parameter of the pyrochlore phase rises from 10.4878 (x = 0.3) to 10.5154 Å (x = 0.7). The samples are characterized by a porous microstructure with indistinct grain boundaries. Zinc oxide has a sintering effect on ceramics. The charge state of the ions in Bi2ZnxFe1-xTa2O9.5-Δ was investigated by X-ray spectroscopy. NEXAFS and XPS data show that zinc doping does not change the oxidation degree of iron and bismuth ions in pyrochlore. The ions are in the charge states Bi(+3), Fe(+3), Zn(+2). In the Ta4fspectrum, an energy shift of the absorption band towards lower energies by ΔE = 0.5 eV is observed, which is typical for tantalum ions with an effective charge of (+5-δ). With the increase of x(Zn), the Bi 4f7/2 and Bi 4f5/2 bands are observed to shift to lower energies due to the distribution of some Zn(II) ions in the bismuth position. Full article
(This article belongs to the Section Inorganic Solid-State Chemistry)
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13 pages, 2183 KiB  
Article
Method for Decontamination of Toxic Aluminochrome Catalyst Sludge by Reduction of Hexavalent Chromium
by Igor Pyagay, Olga Zubkova, Margarita Zubakina and Viktor Sizyakov
Inorganics 2023, 11(7), 284; https://doi.org/10.3390/inorganics11070284 - 30 Jun 2023
Cited by 2 | Viewed by 984
Abstract
The article is devoted to the neutralization of the harmful effects of aluminochrome catalyst sludge. Catalyst sludge is a waste product from petrochemical production and poses a serious threat to the environment and humans because of the toxic hexavalent chromium it contains. The [...] Read more.
The article is devoted to the neutralization of the harmful effects of aluminochrome catalyst sludge. Catalyst sludge is a waste product from petrochemical production and poses a serious threat to the environment and humans because of the toxic hexavalent chromium it contains. The emissions of Russian petrochemical enterprises’ alumochrome sludge is 10,000–12,000 tons per year. In this paper, research related to the possibility of reducing the harmful effects of sludge by converting hexavalent chromium to a less dangerous trivalent state is presented. The reduction of hexavalent chromium was carried out with different reagents: Na2SO3, FeSO4, Na2S2O3, and Na2S2O5. Then, a comparative analysis was carried out, and sodium metabisulfite was chosen as the most preferred reagent. The peculiarity of the reducing method was carrying out the reaction in a neutral medium, pH = 7.0. The reduction was carried out in the temperature range of 60–85 °C and under standard conditions. The maximum recovery efficiency of chromium from the catalyst sludge (100%) was achieved at 85 °C and 10 min. This method did not involve the use of concentrated sulfuric acid, as in a number of common techniques, or additional reagents for the precipitation of chromium in the form of hydroxide. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Inorganic Materials)
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