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Inorganics
Volume 11
Issue 5
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Inorganics, Volume 11, Issue 5 (May 2023) – 47 articles

Cover Story (view full-size image): A 1D Fe2O3-anchored three-dimensional graphene (3DG) hybrid anode is synthesized by hydrothermal and annealing methods. The 3DG enhances the electrical conductivity of Fe2O3, and the combined 1D–3D interpenetrating structure can help enhance the structural stability and accelerate the Li+ diffusion rate. The optimized hybrid electrode gives the lithium-ion batteries higher capacity and longer cycle durability. View this paper
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15 pages, 3040 KiB  
Article
DFT Analysis of the Electronic and Structural Properties of Lanthanide Nitride Cluster Fullerenes Ln3N@C80
by César Martínez-Flores and Vladimir A. Basiuk
Inorganics 2023, 11(5), 223; https://doi.org/10.3390/inorganics11050223 - 22 May 2023
Cited by 2 | Viewed by 1486
Abstract
We have undertaken a DFT study of the nitride cluster fullerenes (NCFs) Ln3N@C80 for the complete series of fourteen lanthanides plus lanthanum by using the PBE functional with the Grimme’s dispersion correction (PBE-D2). We tested the DN and DND basis [...] Read more.
We have undertaken a DFT study of the nitride cluster fullerenes (NCFs) Ln3N@C80 for the complete series of fourteen lanthanides plus lanthanum by using the PBE functional with the Grimme’s dispersion correction (PBE-D2). We tested the DN and DND basis sets, which are equivalent to 6-31G and 6-31G(d) Pople-type basis sets, respectively. Due to the known convergence problems when treating lanthanide-containing systems, only with the DN basis set was it possible to complete the calculations (geometry optimization and analysis of selected electronic parameters) for all the fifteen NCFs. We found that the bending of the Ln3N cluster increases as the ionic radius increases, in general agreement with the available X-ray diffraction data. The Ln3N cluster becomes more planar as the Ln–N bond length is contracted, and the C80 cavity slightly deforms. The HOMO-LUMO energies and distribution, as well as the charge and spin of the encapsulated metal ions, are analyzed. Full article
(This article belongs to the Special Issue Research on Metallofullerenes)
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17 pages, 8750 KiB  
Article
Synthesis, X-ray Structure of Two Hexa-Coordinated Ni(II) Complexes with s-Triazine Hydrazine Schiff Base Ligand
by Eman M. Fathalla, Morsy A. M. Abu-Youssef, Mona M. Sharaf, Ayman El-Faham, Assem Barakat, Matti Haukka and Saied M. Soliman
Inorganics 2023, 11(5), 222; https://doi.org/10.3390/inorganics11050222 - 21 May 2023
Cited by 7 | Viewed by 1884
Abstract
The hydrazine s-triazine ligand (E)-4,4’-(6-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)-1,3,5-triazine-2,4-diyl)dimorpholine (DMPT) was used to synthesize two new Ni(II) complexes via a self-assembly technique. The two complexes were synthesized by a one-pot synthesis strategy and characterized by elemental analysis, FTIR and single-crystal X-ray diffraction analysis to [...] Read more.
The hydrazine s-triazine ligand (E)-4,4’-(6-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)-1,3,5-triazine-2,4-diyl)dimorpholine (DMPT) was used to synthesize two new Ni(II) complexes via a self-assembly technique. The two complexes were synthesized by a one-pot synthesis strategy and characterized by elemental analysis, FTIR and single-crystal X-ray diffraction analysis to be [Ni(DMPT)(H2O)3](NO3)2.3H2O (1) and [Ni(DMPT)(H2O)3](NO3)2.H2O (2). The structures of both complexes were very similar regarding the coordination sphere and counter anions, but differ only in the number of the crystal water molecules. In the case of complex 1, there are three water molecules instead of one H2O molecule as in complex 2. In the two complexes, the DMPT ligand acts as a neutral tridentate NNN-chelate via three Ni–N coordination interactions. The coordination sphere of the Ni(II) ion is completed by three water molecules. As a result, the two complexes exhibit distorted octahedral geometry. The Hirshfeld surfaces around each entity in both complexes have been computed. Subsequently, their corresponding intermolecular interactions were quantified separately. Because the number of crystal water molecules is different in both complexes, their monomeric units are connected differently in their crystal structures where the crystal water molecules act as both hydrogen bond donor and acceptor. The polar O…H interactions are the most dominant in all entities of both complexes. As a result, strong O…H interactions are the driving force in the crystal packing of both complexes, and this is attributed to the presence of the nitrate anions and water molecules. The antimicrobial activity of the free ligand and complex 1 were determined against two selected fungal species, Gram-negative and Gram-positive bacterial strains. The free ligand was found to be inactive against all microbial species. On the other hand, the Ni(II) complex 1 was found active against the Gram-positive bacterial species Bacillus subtilis and also the Gram-negative bacterial species Escherichia coli. The respective inhibition zone diameter of the Ni(II) complex was 12 and 11 mm, respectively. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Coordination Chemistry)
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11 pages, 12876 KiB  
Article
Continuous and Intermittent Planetary Ball Milling Effects on the Alloying of a Bismuth Antimony Telluride Powder Mixture
by Georgios Samourgkanidis and Theodora Kyratsi
Inorganics 2023, 11(5), 221; https://doi.org/10.3390/inorganics11050221 - 20 May 2023
Cited by 3 | Viewed by 1591
Abstract
This study investigates the effects of continuous and in-steps mechanical alloying of a bismuth antimony telluride powder mixture (Bi0.4Sb1.6Te3.0) via the mechanical planetary ball milling (PBM) process as a function of milling time and powder mixture amount. [...] Read more.
This study investigates the effects of continuous and in-steps mechanical alloying of a bismuth antimony telluride powder mixture (Bi0.4Sb1.6Te3.0) via the mechanical planetary ball milling (PBM) process as a function of milling time and powder mixture amount. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the phase, composition, and morphology of the alloy. The alloyed powder with the optimum PBM conditions was then hot pressed (HP), and its thermoelectric properties were further investigated. The results on the alloying of the powder mixture showed that due to the high agglomeration tendency of BST during the PBM process, a significant deviation occurs in the development of a single-phase state over time when the powder mixture is milled continuously and in-steps. ’In-steps’ refers to the procedure of interrupting the PBM process and detaching the agglomerated powder adhering to the inner walls of the vessel. This task was repeated every hour and a half of the PBM process for a total of 12 h, and the results were compared with those of the 12 h continuous PBM process of the same mixture. In addition, the procedure was repeated with different amounts of mixture (100 g and 150 g) to determine the most efficient method of producing the material as a function of time. As for the thermoelectric profile of the powder, the data showed results in direct agreement with those in the literature. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Inorganic Materials)
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17 pages, 1867 KiB  
Article
Structural and Antimicrobial Investigation of Some New Nanoparticles Mixed Ligands Metal Complexes of Ethyl 6-Amino-4-(4-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate in Presence of 1,10-Phenanthroline
by Mohamed S. El-Attar, Sadeek A. Sadeek, Hassan A. El-Sayed, Heba M. Kamal and Hazem S. Elshafie
Inorganics 2023, 11(5), 220; https://doi.org/10.3390/inorganics11050220 - 20 May 2023
Cited by 2 | Viewed by 1639
Abstract
A new series of some biologically active Cr(III), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) complexes was synthesized from the reaction of Ethyl 6-amino-4-(4-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate (L) with the previous biological metals in the presence of 1,10-phenanthroline monohydrate (Phen). The structures of the obtained [...] Read more.
A new series of some biologically active Cr(III), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) complexes was synthesized from the reaction of Ethyl 6-amino-4-(4-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate (L) with the previous biological metals in the presence of 1,10-phenanthroline monohydrate (Phen). The structures of the obtained L along with their complexes were authenticated by different analytical and spectral techniques. The data prove that L chelates with all metal ions as bidentate through the nitrogen of the amino group and the nitrogen of the cyano group. Furthermore, Phen chelated with metal ions via two nitrogen atoms. The molar conductance values reflect that all complexes are electrolyte, confirming the 1:3 electrolytic natures for trivalent metal ions and 1:2 electrolytic for bivalent metal ions. The thermal stability and the general thermal decomposition pathways of metal complexes, L, and Phen were evaluating according to the thermogravimetric technique. The activation thermodynamic parameters were estimated from TG curves by utilizing Horowitz–Metzger (HM) and Coats–Redfern (CR) techniques. Powder X-ray diffraction (XRD) analysis proved that L, Cu(II), and Zn(II) compounds have a crystalline nature, whereas, Cr(III), Fe(III), Co(II), and Ni(II) complexes are semicrystalline. The investigated compounds were examined in vitro for their antimicrobial activity towards G(+ve) Staphylococcus aureus and Bacillus subtilis and G(−ve) Escherichia coli and Pseudomonas aeruginosa bacteria, and two fungi: Candida albicans and Aspergillus flavus. According to the findings, the Co(II) complex has a significant efficiency toward bacteria, additionally, Cr(III) complex is highly significant towards fungal strains. Full article
(This article belongs to the Section Coordination Chemistry)
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12 pages, 4950 KiB  
Article
Electrode with a Carbon Nanotube Array for a Proton Exchange Membrane Fuel Cell
by Adelina A. Zasypkina, Nataliya A. Ivanova, Dmitry D. Spasov, Ruslan M. Mensharapov, Olga K. Alekseeva, Ekaterina A. Vorobyeva, Elena V. Kukueva and Vladimir N. Fateev
Inorganics 2023, 11(5), 219; https://doi.org/10.3390/inorganics11050219 - 19 May 2023
Cited by 4 | Viewed by 1631
Abstract
One of the most important problems in the development of proton exchange membrane fuel cells remains the selection of an efficient electrocatalyst support capable of providing a low loading of active metal with minimal changes in the electrochemical surface, electronic conductivity, and activity. [...] Read more.
One of the most important problems in the development of proton exchange membrane fuel cells remains the selection of an efficient electrocatalyst support capable of providing a low loading of active metal with minimal changes in the electrochemical surface, electronic conductivity, and activity. In this work, carbon nanotube arrays (CNTAs) grown directly on commercial gas diffusion layers (GDLs) are used to form electrodes of a new type. The CNTAs are used in the electrode as a microporous layer. The catalytic layer is formed in the microporous layer by a method that does not destroy the carbon support structure and consists of the controlled impregnation of CNTAs with the Pt-precursor with subsequent reduction in platinum particles in the surface volume of the layer. The resulting electrode was studied by scanning/transmission electron microscopy and Raman spectroscopy. This electrode provides increased electrical conductivity of the layer and can also improve stability and longer service life due to the enhanced adhesion of carbon materials to the GDL. Full article
(This article belongs to the Section Inorganic Materials)
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11 pages, 2932 KiB  
Article
Fluorescence Resonance Energy Transfer Properties and Auger Recombination Suppression in Supraparticles Self-Assembled from Colloidal Quantum Dots
by Xinhua Tian, Hao Chang, Hongxing Dong, Chi Zhang and Long Zhang
Inorganics 2023, 11(5), 218; https://doi.org/10.3390/inorganics11050218 - 18 May 2023
Cited by 1 | Viewed by 2269 | Correction
Abstract
Colloid quantum dots (CQDs) are recognized as an ideal material for applications in next-generation optoelectronic devices, owing to their unique structures, outstanding optical properties, and low-cost preparation processes. However, monodisperse CQDs cannot meet the requirements of stability and collective properties for device applications. [...] Read more.
Colloid quantum dots (CQDs) are recognized as an ideal material for applications in next-generation optoelectronic devices, owing to their unique structures, outstanding optical properties, and low-cost preparation processes. However, monodisperse CQDs cannot meet the requirements of stability and collective properties for device applications. Therefore, it is urgent to build stable 3D multiparticle systems with collective physical and optical properties, which is still a great challenge for nanoscience. Herein, we developed a modified microemulsion template method to synthesize quantum dot supraparticles (QD-SPs) with regular shapes and a high packing density, which is an excellent research platform for ultrafast optical properties of composite systems. The redshift of the steady-state fluorescence spectra of QD-SPs compared to CQD solutions indicates that fluorescence resonance energy transfer (FRET) occurred between the CQDs. Moreover, we investigated the dynamic processes of energy transfer in QD-SPs by time-resolved ultrafast fluorescence spectroscopy. The dynamic redshift and lifetime changes of the spectra further verified the existence of rapid energy transfer between CQDs with different exciton energies. In addition, compared with CQD solutions, the steady-state fluorescence lifetime of SPs increased and the fluorescence intensity decreased slowly with increasing temperature, which indicates that the SP structure suppressed the Auger recombination of CQDs. Our results provide a practical approach to enhance the coupling and luminescence stability of CQDs, which may enable new physical phenomena and improve the performance of optoelectronic devices. Full article
(This article belongs to the Special Issue Advanced Inorganic Semiconductor Materials)
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17 pages, 6317 KiB  
Article
Tetragonal Nanosized Zirconia: Hydrothermal Synthesis and Its Performance as a Promising Ceramic Reinforcement
by Shikai Liu, Jialin Wang, Yingxin Chen, Zhijian Song, Bibo Han, Haocheng Wu, Taihang Zhang and Meng Liu
Inorganics 2023, 11(5), 217; https://doi.org/10.3390/inorganics11050217 - 17 May 2023
Cited by 6 | Viewed by 1716
Abstract
In this study, we produced zirconia nanoparticles with a pure tetragonal phase, good dispersion, and an average particle size of approximately 7.3 nm using the modified hydrothermal method. Zirconium oxychloride (ZrOCl2-8H2O) was used as zirconium source, while propanetriol was [...] Read more.
In this study, we produced zirconia nanoparticles with a pure tetragonal phase, good dispersion, and an average particle size of approximately 7.3 nm using the modified hydrothermal method. Zirconium oxychloride (ZrOCl2-8H2O) was used as zirconium source, while propanetriol was used as an additive. The influence of propanetriol content, sonication time, hydrothermal temperature, and type of dispersant on the physical phase and dispersibility of zirconia nanoparticles was investigated. Monoclinic zirconia was found to completely transform into a tetragonal structure when the mass fraction of glycerol was increased to 5 wt%. With the increase in the mechanical stirring time under ultrasonic conditions, the size distribution range of the prepared particles became narrower and then wider, and the particle size became first smaller and then larger. Ultrasonic and mechanical stirring for 5 min had the best effect. When comparing the effects of different dispersants (PEG8000, PVP, and CTAB), it was found that the average particle size of zirconia nanoparticles prepared with 0.5 wt% PVP was the smallest. Furthermore, by adding different concentrations of pure tetragonal phase nanozirconia to 3Y-ZrO2 as reinforcement additives, the bending strength of the prepared ceramics increased first and then decreased with increasing addition amounts. When the amount of addition was 1 wt% and the ceramic was calcined at 1600 °C, the flexural strength of the ceramic increased significantly, which was about 1.6 times that of the unadded ceramic. The results are expected to provide a reference for the reinforcement of high-purity zirconia ceramics. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Inorganic Materials)
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9 pages, 2837 KiB  
Article
Liquid Channels Built-In Solid Magnesium Hydrides for Boosting Hydrogen Sorption
by Zhi-Kang Qin, Li-Qing He, Xiao-Li Ding, Ting-Zhi Si, Ping Cui, Hai-Wen Li and Yong-Tao Li
Inorganics 2023, 11(5), 216; https://doi.org/10.3390/inorganics11050216 - 17 May 2023
Cited by 3 | Viewed by 1677
Abstract
Realizing rapid and stable hydrogen sorption at low temperature is critical for magnesium-based hydrogen storage materials. Herein, liquid channels are built in magnesium hydride by introducing lithium borohydride ion conductors as an efficient route for improving its hydrogen sorption. For instance, the 5 [...] Read more.
Realizing rapid and stable hydrogen sorption at low temperature is critical for magnesium-based hydrogen storage materials. Herein, liquid channels are built in magnesium hydride by introducing lithium borohydride ion conductors as an efficient route for improving its hydrogen sorption. For instance, the 5 wt% LiBH4-doped MgH2 can release about 7.1 wt.% H2 within 40 min at 300 °C but pure MgH2 only desorbs less than 0.7 wt.% H2, and more importantly it delivers faster desorption kinetics with more than 10 times enhancement to pure MgH2. The hydrogen absorption capacity of LiBH4-doped MgH2 can still be well kept at approximately 7.2 wt.% without obvious capacity degradation even after six absorption and desorption cycles. This approach is not only through building ion transfer channels as a hydrogen carrier for kinetic enhancement but also by inhibiting the agglomeration of MgH2 particles to obtain stable cyclic performance, which brings further insights to promoting the hydrogen ab-/desorption of other metal hydrides. Full article
(This article belongs to the Special Issue State-of-the-Art and Progress in Metal-Hydrogen Systems)
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14 pages, 1424 KiB  
Article
Periodic Density Functional Theory (PDFT) Simulating Crystal Structures with Microporous CHA Framework: An Accuracy and Efficiency Study
by Xiao-Fang Chen
Inorganics 2023, 11(5), 215; https://doi.org/10.3390/inorganics11050215 - 16 May 2023
Cited by 46 | Viewed by 1666
Abstract
The structure property is the fundamental factor in determining the stability, adsorption, catalytic performance, and selectivity of microporous materials. Seven density functional approximations (DFAs) are used to simulate the crystal structure of microporous material for examining the efficiency and accuracy. In comparison with [...] Read more.
The structure property is the fundamental factor in determining the stability, adsorption, catalytic performance, and selectivity of microporous materials. Seven density functional approximations (DFAs) are used to simulate the crystal structure of microporous material for examining the efficiency and accuracy. In comparison with the existing zeolites, microporous materials with CHA framework are selected as the testing model. The calculation results indicate that the least lattice volume deviation is 5.18/2.72 Å3 from PBE_mGGA, and the second least is −5.55/−10.36 Å3 from LDA_PP. Contrary to USPP_LDA, PBE_GW, PAW_PBE, and PAW_GGA overestimate the lattice volume by ~15.00–20.00 Å3. For each method, RMS deviations are less than 0.016 Å for bond length and less than 2.813° for bond angle. To complete the crystal structure calculation, the CPU time reduces in order of USPP_GGA > PBE_GW > PAW_GGA, PBE_mGGA > PAW_PBE > LDA_PP > USPP_LDA. For two testing models, when the calculation time is not important, PBE_mGGA is the best choice, and when the tradeoff between accuracy and efficiency is considered, LDA_PP is preferred. It seems feasible and efficient to simulate the zeolite structure through E-V curve fitting, full optimization, and phonon analysis bythe periodic density functional theory. Full article
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20 pages, 2921 KiB  
Review
Research Progress on the Synthesis of Nanosized and Hierarchical Beta Zeolites
by Luwei Hong, Jiazhong Zang, Bin Li, Guanfeng Liu, Yinbin Wang and Luming Wu
Inorganics 2023, 11(5), 214; https://doi.org/10.3390/inorganics11050214 - 16 May 2023
Cited by 5 | Viewed by 2702
Abstract
Beta zeolite, a crystal material with a three-dimensional twelve-ring cross-channel structure, has many advantages, such as high Brønsted acid concentration, high Si/Al ratio, thermal/hydrothermal stability, and large surface area. Due to these advantages, beta zeolite shows excellent catalytic performance in petroleum refining and [...] Read more.
Beta zeolite, a crystal material with a three-dimensional twelve-ring cross-channel structure, has many advantages, such as high Brønsted acid concentration, high Si/Al ratio, thermal/hydrothermal stability, and large surface area. Due to these advantages, beta zeolite shows excellent catalytic performance in petroleum refining and petrochemical processes. However, traditionally microporous beta zeolite has strong steric hindrance and diffusion restrictions, which hinder large molecules from passing through its internal channels. In addition, carbon deposition occurs, resulting in catalyst deactivation. The main strategy to solve this problem is to prepare nanosized or hierarchical beta zeolites, which allow for large molecule conversion and shortening diffusion pathways. Therefore, researchers have explored different synthesis strategies to prepare beta zeolite with different particle sizes and porosities to obtain better zeolite catalysts. This paper briefly describes the recent research progress in the preparation of nanosized and hierarchical beta zeolite. Additionally, the mechanisms of various preparation methods, structural characteristics, and applications of the materials are introduced in detail. Furthermore, the main problems existing in its industrial application are describing by comparing the advantages and disadvantages of the different methods to prepare optimally nanosized and hierarchical zeolite to meet the requirements of industrial development. Full article
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11 pages, 5174 KiB  
Article
Fabrication of ZnWO4-SnO2 Core–Shell Nanorods for Enhanced Solar Light-Driven Photoelectrochemical Performance
by Bathula Babu, Shaik Gouse Peera and Kisoo Yoo
Inorganics 2023, 11(5), 213; https://doi.org/10.3390/inorganics11050213 - 15 May 2023
Cited by 2 | Viewed by 1301
Abstract
This article describes the effective synthesis of colloidal SnO2 quantum dots and ZnWO4 nanorods using wet chemical synthesis and hydrothermal synthesis, respectively. The resulting ZnWO4-SnO2 core–shell nanorod heterostructure is then made, and its structural, optical, and morphological properties [...] Read more.
This article describes the effective synthesis of colloidal SnO2 quantum dots and ZnWO4 nanorods using wet chemical synthesis and hydrothermal synthesis, respectively. The resulting ZnWO4-SnO2 core–shell nanorod heterostructure is then made, and its structural, optical, and morphological properties are assessed using XRD, SEM, TEM, and DRS. The heterojunction’s structural confinement increases the exposure of its reactive sites, and its electronic confinement promotes its redox activity. The heterostructure subsequently exhibits a smaller bandgap and better light-harvesting capabilities, resulting in increased photoelectrochemical performance. The heterostructure of core–shell nanorods shows promise for usage in a range of optoelectronic devices and effective solar energy conversion. Full article
(This article belongs to the Special Issue Optoelectronic Properties of Metal Oxide Semiconductors)
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14 pages, 4253 KiB  
Article
The Role of Non-Covalent Interactions in the Reactions between Palladium Hydrido Complex with Amidoarylphosphine Pincer Ligand and Brønsted Acids
by Vladislava A. Kirkina, Vasilisa A. Kulikova, Evgenii I. Gutsul, Zufar N. Gafurov, Ilias F. Sakhapov, Dmitry G. Yakhvarov, Yulia V. Nelyubina, Oleg A. Filippov, Elena S. Shubina and Natalia V. Belkova
Inorganics 2023, 11(5), 212; https://doi.org/10.3390/inorganics11050212 - 15 May 2023
Cited by 5 | Viewed by 1719
Abstract
The interaction between (PNP)PdH (1); PNP = bis(2-diisopropylphosphino-4-methylphenyl)amide and different acids (CF3SO3H, HBF4∙Et2O, fluorinated alcohols and formic acid) was studied in benzene or toluene as well as in neat alcohols by IR and [...] Read more.
The interaction between (PNP)PdH (1); PNP = bis(2-diisopropylphosphino-4-methylphenyl)amide and different acids (CF3SO3H, HBF4∙Et2O, fluorinated alcohols and formic acid) was studied in benzene or toluene as well as in neat alcohols by IR and NMR spectroscopies. The structures of hydrogen-bonded complexes were also optimized at the DFT/ωB97-XD/def2-TZVP level. The nitrogen atom of the amidophosphine pincer ligand readily accepts proton not only from strong Brønsted acids but from relatively weak fluorinated alcohols. That suggests that binding to palladium(II) increases the diarylamine basicity, making it a strong base. Nevertheless, H+ can be taken from [(PN(H)P)PdH]+ (2) by pyridine or hexamethylphosphoramide (HMPA). These observations confirm the need for a shuttle base to form [(PN(H)P)PdH]+ (2) as the result of the heterolytic splitting of H2 by [(PNP)Pd]+. At that, a stoichiometric amount of formic acid protonates a hydride ligand yielding an unstable η2-H2 complex that rapidly converts into formate (PNP)Pd(OCHO), which loses CO2 to restore (PNP)PdH, whereas the relatively high acid excess hampers this reaction through competitive protonation at nitrogen atom. Full article
(This article belongs to the Special Issue Revealing Reaction Mechanisms in Homogeneous Transition Metal Catalysis, 2nd Edition)
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13 pages, 4002 KiB  
Article
Temperature-Driven Synthesis of 1D Fe2O3@3D Graphene Composite Applies as Anode of Lithium-Ion Batteries
by Shengyuan Zhu, Ruizhi Li, Jiapeng Xu, Liu Yang and Yingke Zhou
Inorganics 2023, 11(5), 211; https://doi.org/10.3390/inorganics11050211 - 13 May 2023
Viewed by 1358
Abstract
A series of Fe2O3-anchored three-dimensional graphene (3DG) composites are synthesized via hydrothermal and annealing methods. The Fe2O3 nanocrystals in composites display nanocubes, one-dimensional (1D) nanorods and ellipsoids at hydrothermal temperatures of 120 °C, 150 °C and [...] Read more.
A series of Fe2O3-anchored three-dimensional graphene (3DG) composites are synthesized via hydrothermal and annealing methods. The Fe2O3 nanocrystals in composites display nanocubes, one-dimensional (1D) nanorods and ellipsoids at hydrothermal temperatures of 120 °C, 150 °C and 180 °C, respectively. Notably, the composite synthesized at 150 °C shows 1D Fe2O3 uniformly embedded in 3DG, forming an interpenetrating 1D-3D (three-dimensional) structure. This combined structure is beneficial in improving the electrochemical stability and accelerating the Li+ diffusion rate. When used as anode for lithium-ion batteries (LIBs), the optimized 1D-3D Fe2O3@3DG composite delivers a reversible specific capacity of 1041 mAh g−1 at 0.1 A g−1 and maintains a high reversible specific capacity of 775 mAh g−1 after 200 cycles. The superior electrochemical properties of Fe2O3@3DG are a result of the stable interpenetrate structure, enhanced conductivity, and buffered volume change. These results suggest that Fe2O3@3DG composites have significant potential as advanced anode materials for LIBs and the combined 1D-3D structure also provides inspiration for other electrode material structure design. Full article
(This article belongs to the Special Issue Recent Advances in Energy Storage and Conversion)
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18 pages, 15896 KiB  
Article
Preparation and Application of Fe-Al-SiO2 Poly-Coagulants for Removing Microcystis aeruginosa from Water
by Yuhan Zhang, Xiaobao Nie, Shiquan Sun, Wei Zhang, Xin Fang and Junli Wan
Inorganics 2023, 11(5), 210; https://doi.org/10.3390/inorganics11050210 - 13 May 2023
Viewed by 1367
Abstract
Novel Fe-Al-SiO2 (FAS) poly-coagulants were prepared by the ball milling method using ferrous sulfate, aluminum sulfate, hydrophobic silica, and sodium carbonate as raw materials. The optimal preparation conditions and effects of preparation parameters on removal efficiencies were obtained by Response Surface Methodology [...] Read more.
Novel Fe-Al-SiO2 (FAS) poly-coagulants were prepared by the ball milling method using ferrous sulfate, aluminum sulfate, hydrophobic silica, and sodium carbonate as raw materials. The optimal preparation conditions and effects of preparation parameters on removal efficiencies were obtained by Response Surface Methodology (RSM) and Analysis of Variance (ANOVA). Removal efficiencies were investigated by employing FAS as the poly-coagulant for algae-laden water. Furthermore, obtained FAS samples were characterized by SEM, FTIR, XRD, and TGA. Results showed that the optimal preparation conditions were n(Fe):n(Al) of 2:1, m(Si):m(Fe+Al) of 1:2, and n(CO32−):n(Fe+Al) of 1.75:1, and the most significant influencing factor was n(CO32−):n(Fe+Al). FAS13 prepared under the above condition had the highest coagulation efficiency for simulated algae-laden water. Removal efficiencies for OD680, TP, and residual Al and Fe concentrations were 92.86%, 90.55%, 0.142 mg/L, and 0.074 mg/L, respectively. Nano-sized spherical particles, excellent thermal stability, and functional groups such as Al–O–Si, Fe–O–Si, and Fe–OH, corresponding to Al2Si2O5(OH)4, Fe7Si8O22(OH)2, and Fe2(OH)2CO3, were observed in FAS13. The coagulation performance of FAS13 was splendid when applied in real algae-laden water. The removal rates of TP, OD680, turbidity, and Chl-α were above 93.87%. The residual Al concentration was at the range of 0.057–0.128 mg/L. Full article
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17 pages, 5497 KiB  
Article
Chalcogen Bonds, Halogen Bonds and Halogen···Halogen Contacts in Di- and Tri-iododiorganyltellurium(IV) Derivatives
by Sergi Burguera, Rosa M. Gomila, Antonio Bauzá and Antonio Frontera
Inorganics 2023, 11(5), 209; https://doi.org/10.3390/inorganics11050209 - 12 May 2023
Cited by 4 | Viewed by 1725
Abstract
In this manuscript, we have examined the CSD (Cambridge Structural Database) to investigate the relative ability of Te and I (in practice, the heaviest chalcogen and halogen atoms) in di- and tri-iododiorganyltellurium(IV) derivatives to establish σ-hole interactions. The geometry around the Te(IV) in [...] Read more.
In this manuscript, we have examined the CSD (Cambridge Structural Database) to investigate the relative ability of Te and I (in practice, the heaviest chalcogen and halogen atoms) in di- and tri-iododiorganyltellurium(IV) derivatives to establish σ-hole interactions. The geometry around the Te(IV) in this type of compound is trigonal bipyramidal where the stereoactive lone pair at Te(IV) occupies one of the equatorial positions. In the solid state, Te(IV) tends to form pseudo-octahedral coordination by establishing strong noncovalent interactions opposite to the two covalent bonds of the equatorial plane. Such contacts can also be classified as chalcogen bonds following the recommendation of the International Union of Pure and Applied Chemistry (IUPAC). Such contacts have been analyzed energetically in this work using density functional theory (DFT) calculations, rationalized using molecular electrostatic potential (MEP) surface analysis and characterized using a combination of the quantum theory of atoms in molecules (QTAIM) and noncovalent interaction plot (NCIplot) computational tools. Finally, the observation of halogen bonds and type I halogen···halogen contacts is also emphasized and compared to the chalcogen bonds. Energy decomposition analysis has also been performed to compare the physical nature of chalcogen, halogen and type I interactions. Full article
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19 pages, 4858 KiB  
Article
Interaction of Redox-Active Copper(II) with Catecholamines: A Combined Spectroscopic and Theoretical Study
by Miriama Šimunková, Zuzana Barbieriková, Milan Mazúr, Marian Valko, Suliman Y. Alomar, Saleh H. Alwasel and Michal Malček
Inorganics 2023, 11(5), 208; https://doi.org/10.3390/inorganics11050208 - 12 May 2023
Cited by 2 | Viewed by 1624
Abstract
In this work, attention is focused on the non-essential amino acid L-Tyrosine (TYR) hydroxylated to L-DOPA, which is the precursor to the neurotransmitters dopamine, noradrenaline (norepinephrine; NE) and adrenaline (epinephrine; EP) known as catecholamines and their interactions with redox-active Cu(II). Catecholamines have multiple [...] Read more.
In this work, attention is focused on the non-essential amino acid L-Tyrosine (TYR) hydroxylated to L-DOPA, which is the precursor to the neurotransmitters dopamine, noradrenaline (norepinephrine; NE) and adrenaline (epinephrine; EP) known as catecholamines and their interactions with redox-active Cu(II). Catecholamines have multiple functions in biological systems, including the regulation of the central nervous system, and free (unbound) redox metal ions are present in many diseases with disturbed metal homeostasis. The interaction between catecholamines and Cu(II) has been studied by means of Electron Paramagnetic Resonance spectroscopy (EPR), EPR spin trapping and UV-vis spectroscopy. The obtained spectroscopic results are supported by Density Functional Theory calculations. Only minor qualitative and quantitative changes in the UV-vis spectra of all the studied compounds have been observed following their interactions with Cu(II) ions. The low-temperature EPR spectra were more convincing and confirmed the interaction between Cu(II) ions and all the studied compounds, involving hydroxyl groups and amino nitrogens. The use of an ABTS assay revealed that the compounds under study possessed radical-scavenging activities against ABTS•+ in the order TYR < EP < DA < NE~L-DOPA. The neurotransmitters DA, NE and EP, following their interaction with Cu(II), exhibit the ability to (partially) reduce Cu(II) to Cu(I) species which was confirmed using the Cu(I) specific chelator neocuproine. EPR spin-trapping experiments revealed the suppressed formation of hydroxyl radicals (•OH) in a copper(II) catalyzed Fenton-like system in the presence of catecholamines. Only in the case of EP was autooxidation in a stock solution observed. Furthermore, the oxidation of EP is enhanced in the presence of Cu(II) ions. In conclusion, it has been confirmed that the oxidation of catecholamines in the presence of copper promotes the redox cycling process, resulting in the formation of ROS, which may, in turn, cause damage to neuronal systems. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Bioinorganic Chemistry)
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15 pages, 9033 KiB  
Article
Crystal Structure and XPS Study of Titanium-Substituted M-Type Hexaferrite BaFe12−xTixO19
by Kim-Isabelle Mehnert, Manuel Häßner, Yanina Mariella Dreer, Indro Biswas and Rainer Niewa
Inorganics 2023, 11(5), 207; https://doi.org/10.3390/inorganics11050207 - 10 May 2023
Cited by 6 | Viewed by 2001
Abstract
The M-type barium hexaferrite substituted with titanium, BaFe12−xTixO19, was synthesized from sodium carbonate flux and the obtained single crystals with a maximum degree of substitution of up to about x = 0.9 were characterized. XPS [...] Read more.
The M-type barium hexaferrite substituted with titanium, BaFe12−xTixO19, was synthesized from sodium carbonate flux and the obtained single crystals with a maximum degree of substitution of up to about x = 0.9 were characterized. XPS measurements were carried out for the identification of side products and in particular in order to assign the valence states of the transition-metal constituents. Due to the aliovalent exchange of iron(III) with titanium(IV), an additional charge balance needs to occur. No titanium(III) was detected, while the amount of iron(II) increased in the same order of magnitude as the amount of titanium(IV); thus, the major charge balancing is attributed to the reduction of iron(III) to iron(II). According to the XPS data, the amount of titanium(IV) typically is slightly higher than that of iron(II). This is in line with a tendency to a minor formation of vacancies on the transition-metal sites becoming more important at higher substitution levels according to PXRD and WDS measurements, completing the picture of the charge-balance mechanism. XRD taken on single crystals indicates the distribution of titanium and vacancies over three of the five transition-metal sites. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Inorganic Solid State Chemistry)
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14 pages, 5727 KiB  
Article
Surface Plasmon Resonance Effect of Noble Metal (Ag and Au) Nanoparticles on BiVO4 for Photoelectrochemical Water Splitting
by Rui Liu, Difu Zhan, Dong Wang, Changcun Han, Qian Fu, Hongxun Zhu, Zhuxiang Mao and Zhao-Qing Liu
Inorganics 2023, 11(5), 206; https://doi.org/10.3390/inorganics11050206 - 10 May 2023
Cited by 2 | Viewed by 2069
Abstract
Photoelectrochemical (PEC) splitting water technology over the years has gradually matured, and now photoanodes loaded with nanoparticles (NPs) show excellent PEC performance. Each of the metal NPs has a different effect on the PEC performance of BiVO4. This work selected the [...] Read more.
Photoelectrochemical (PEC) splitting water technology over the years has gradually matured, and now photoanodes loaded with nanoparticles (NPs) show excellent PEC performance. Each of the metal NPs has a different effect on the PEC performance of BiVO4. This work selected the noble metals Ag and Au to modify BiVO4 and study its PEC performance. After recombination, the photocurrent densities of Ag/BiVO4 and Au/BiVO4 photoanodes were 3.88 mA/cm2 and 1.61 mA/cm2 at 1.23 VRHE, which were 3.82 and 1.72 times that of pure BiVO4. The hydrogen evolution of pure BiVO4 is about 1.10 μmol·cm−2. Ag/BiVO4 and Au/BiVO4 contain 3.56 and 2.32 times pure BiVO4, respectively. Through the research, it was found that the composite noble metal (NM) NPs could improve the PEC properties; this is because NM NPs can introduce a surface plasmon resonance (SPR) effect to increase the concentration and accelerate the separation of carriers. The mechanism of the SPR effect can be explained as NM NPs are excited by light generating “hot electrons”, and the hot electrons can directly enter the conduction band (CB) of BiVO4 through an electron transfer mechanism. The potential energy of the Schottky barrier generated by the contact of NM NPs with BiVO4 is smaller than that generated by the SPR effect, which enables the “hot electrons” to be smoothly transferred from the NM NPs to the conduction band of BiVO4 without returning to the NM NPs. Ag/BiVO4 showed higher PEC activity than Au/BiVO4 because of its higher light absorption, photocurrent, and oxygen evolution capacity. It can be seen that loading NM NPs increases the concentration of the carriers while the separation and transfer rates of the carriers are improved. In conclusion, it was concluded from this study that the loading of NM NPs is an effective method to improve the water oxidation kinetics of BiVO4 photoanodes. Full article
(This article belongs to the Special Issue Photoelectrodes for Water Splitting)
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16 pages, 6318 KiB  
Article
Synthesis, Crystal Structure and Photoluminescent Properties of Red-Emitting CaAl4O7:Cr3+ Nanocrystalline Phosphor
by Leonid Vasylechko, Vitalii Stadnik, Vasyl Hreb, Yaroslav Zhydachevskyy, Andriy Luchechko, Vitaliy Mykhaylyk, Hans Kraus and Andrzej Suchocki
Inorganics 2023, 11(5), 205; https://doi.org/10.3390/inorganics11050205 - 9 May 2023
Cited by 3 | Viewed by 1695
Abstract
Calcium dialuminate, CaAl4O7, nanopowders with a grossite-type structure, doped with chromium ions, were synthesized via the combined sol–gel solution combustion method. The evolution of phase composition, crystal structure, and microstructural parameters of the nanocrystalline materials depending on the temperature [...] Read more.
Calcium dialuminate, CaAl4O7, nanopowders with a grossite-type structure, doped with chromium ions, were synthesized via the combined sol–gel solution combustion method. The evolution of phase composition, crystal structure, and microstructural parameters of the nanocrystalline materials depending on the temperature of the thermal treatment was investigated via X-ray powder diffraction and applying the Rietveld refinement technique. The photoluminescent properties of CaAl4O7 nanophosphors activated with Cr3+ ions were studied over the temperature range of 4.5–325 K. The samples show deep red and near-infrared luminescence due to the 2E → 4A2 and 4T2 → 4A2 energy level transitions of Cr3+ ions under excitation in the two broad emission bands in the visible spectral region. The R lines emission reveals a strong temperature dependence. The feasibility of the material for non-contact luminescence sensing is investigated, and good sensitivity is obtained based on the (R2/R1) luminescence intensity ratio and the lifetime of the emission. Full article
(This article belongs to the Special Issue Mixed Metal Oxides II)
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10 pages, 2550 KiB  
Article
Enhanced Thermal Stability of Sputtered TiN Thin Films for Their Applications as Diffusion Barriers against Copper Interconnect
by Abdullah Aljaafari, Faheem Ahmed, Nagih M. Shaalan, Shalendra Kumar and Abdullah Alsulami
Inorganics 2023, 11(5), 204; https://doi.org/10.3390/inorganics11050204 - 9 May 2023
Cited by 3 | Viewed by 2441
Abstract
In this work, the deposition of titanium nitride (TiN) thin film using direct current (DC) sputtering technique and its application as diffusion barriers against copper interconnect was presented. The deposited film was analyzed by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), [...] Read more.
In this work, the deposition of titanium nitride (TiN) thin film using direct current (DC) sputtering technique and its application as diffusion barriers against copper interconnect was presented. The deposited film was analyzed by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS) techniques. XRD patterns showed the face-centered cubic (FCC) structure for the TiN/SiO2/Si film, having (111) and (200) peaks and TiN (111), Cu(111), and Cu(200) peaks for Cu/TiN/SiO2/Si film. FESEM images revealed that the grains were homogeneously dispersed on the surface of the TiN film, having a finite size. XPS study showed that Ti2p doublet with peaks centered at 455.1 eV and 461.0 eV for TiN film was observed. Furthermore, the stoichiometry of the deposited TiN film was found to be 0.98. The sheet resistance of the TiN film was analyzed by using a four-point probe method, and the resistivity was calculated to be 11 μΩ cm. For the utilization, TiN film were tested for diffusion barrier performance against Cu interconnect. The results exhibited that TiN film has excellent performance in diffusion barrier for copper metallization up to a temperature of 700 °C. However, at a higher annealing temperature of 800 °C, the formation of Cu3Si and TiSi2 compounds were evident. Thus, stoichiometric TiN film with high thermal stability and low resistivity produced in this study could be applied for the fabrication of microelectronic devices. Full article
(This article belongs to the Special Issue 10th Anniversary of Inorganics: Inorganic Materials)
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12 pages, 3437 KiB  
Article
Doping with Rare Earth Elements and Loading Cocatalysts to Improve the Solar Water Splitting Performance of BiVO4
by Meng Wang, Lan Wu, Feng Zhang, Lili Gao, Lei Geng, Jiabao Ge, Kaige Tian, Huan Chai, Huilin Niu, Yang Liu and Jun Jin
Inorganics 2023, 11(5), 203; https://doi.org/10.3390/inorganics11050203 - 7 May 2023
Cited by 6 | Viewed by 2767
Abstract
BiVO4 is a highly promising material for Photoelectrochemical (PEC) water splitting photoanodes due to its narrow band gap value (~2.4 eV) and its ability to efficiently absorb visible light. However, the short hole migration distance, severe surface complexation, and low carrier separation [...] Read more.
BiVO4 is a highly promising material for Photoelectrochemical (PEC) water splitting photoanodes due to its narrow band gap value (~2.4 eV) and its ability to efficiently absorb visible light. However, the short hole migration distance, severe surface complexation, and low carrier separation efficiency limit its application. Therefore, in this paper, BiVO4 was modified by loading CoOOH cocatalyst on the rare earth element Nd-doped BiVO4 (Nd-BiVO4) photoanode. The physical characterization and electrochemical test results showed that Nd doping will cause lattice distortion of BiVO4 and introduce impurity energy levels to capture electrons to increase carrier concentration, thereby improving carrier separation efficiency. Further loading of surface CoOOH cocatalyst can accelerate charge separation and inhibit electron–hole recombination. Ultimately, the prepared target photoanode (CoOOH-Nd-BiVO4) exhibits an excellent photocurrent density (2.4 mAcm−2) at 1.23 V versus reversible hydrogen electrode potential (vs. RHE), which is 2.67 times higher than that of pure BiVO4 (0.9 mA cm−2), and the onset potential is negatively shifted by 214 mV. The formation of the internal energy states of rare earth metal elements can reduce the photoexcited electron–hole pair recombination, so as to achieve efficient photochemical water decomposition ability. CoOOH is an efficient and suitable oxygen evolution cocatalyst (OEC), and OEC decoration of BiVO4 surface is of great significance for inhibiting surface charge recombination. This work provides a new strategy for achieving effective PEC water oxidation of BiVO4. Full article
(This article belongs to the Special Issue Photoelectrodes for Water Splitting)
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11 pages, 8222 KiB  
Article
Release of Pure H2 from Na[BH3(CH3NH)BH2(CH3NH)BH3] by Introduction of Methyl Substituents
by Ting Zhang, Timothy Steenhaut, Michel Devillers and Yaroslav Filinchuk
Inorganics 2023, 11(5), 202; https://doi.org/10.3390/inorganics11050202 - 7 May 2023
Viewed by 1371
Abstract
Over the last 10 years, hydrogen-rich compounds based on five-membered boron–nitrogen chain anions have attracted attention as potential hydrogen storage candidates. In this work, we synthesized Na[BH3(CH3NH)BH2(CH3NH)BH3] through a simple mechanochemical approach. The [...] Read more.
Over the last 10 years, hydrogen-rich compounds based on five-membered boron–nitrogen chain anions have attracted attention as potential hydrogen storage candidates. In this work, we synthesized Na[BH3(CH3NH)BH2(CH3NH)BH3] through a simple mechanochemical approach. The structure of this compound, obtained through synchrotron powder X-ray diffraction, is presented here for the first time. Its hydrogen release properties were studied by thermogravimetric analysis and mass spectrometry. It is shown here that Na[BH3(CH3NH)BH2(CH3NH)BH3], on the contrary of its parent counterpart, Na[BH3NH2BH2NH2BH3], is able to release up to 4.6 wt.% of pure hydrogen below 150 °C. These results demonstrate that the introduction of a methyl group on nitrogen atom may be a good strategy to efficiently suppress the release of commonly encountered undesired gaseous by-products during the thermal dehydrogenation of B-N-H compounds. Full article
(This article belongs to the Special Issue State-of-the-Art and Progress in Metal-Hydrogen Systems)
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14 pages, 4454 KiB  
Article
Theoretical Insight on the Formation Mechanism of a Trisubstituted Derivative of Closo-Decaborate Anion [B10H7O2CCH3(NCCH3)]0
by Ilya N. Klyukin, Anastasia V. Kolbunova, Alexander S. Novikov, Andrey P. Zhdanov, Konstantin Yu. Zhizhin and Nikolay T. Kuznetsov
Inorganics 2023, 11(5), 201; https://doi.org/10.3390/inorganics11050201 - 6 May 2023
Cited by 2 | Viewed by 1493
Abstract
A theoretical modelling of the interaction process between a protonated complex of carboxonium derivative [2,6-B10H8O2CCH3*Hfac]0 and acetonitrile molecule CH3CN was carried out. As a result of the process, a trisubstituted [...] Read more.
A theoretical modelling of the interaction process between a protonated complex of carboxonium derivative [2,6-B10H8O2CCH3*Hfac]0 and acetonitrile molecule CH3CN was carried out. As a result of the process, a trisubstituted [B10H7O2CCH3(NCCH3)]0 derivative was formed. This reaction has an electrophile-induced nucleophilic substitution (EINS) mechanism. The main intermediates and transition states of the substitution process were established. As in the case of all previously investigated EINS processes, the key intermediate was an anion with a dihydrogen H2 fragment attached to one boron atom (B(H2) structure motif). The process of nucleophilic substitution can proceed on a different position of the cluster cage. The main potential pathways were assessed. It was established that substitution on the B4 position of the cluster cage was the most energetically favourable, and the [2,4,6-B10H7O2CCH3(NCCH3)]0 isomer was formed. Full article
(This article belongs to the Special Issue Experimental and Theoretical Studies of Main and Transition Group Elements Cluster Compounds)
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12 pages, 2623 KiB  
Article
Calcium-Based Sorbent Carbonation at Low Temperature via Reactive Milling under CO2
by Seyed Morteza Taghavi Kouzehkanan, Ehsan Hassani, Farshad Feyzbar-Khalkhali-Nejad and Tae-Sik Oh
Inorganics 2023, 11(5), 200; https://doi.org/10.3390/inorganics11050200 - 3 May 2023
Cited by 5 | Viewed by 1861
Abstract
The carbonation behavior of calcium-containing sorbents, CaO and Ca(OH)2, was investigated under pressurized CO2 at nominal room temperature. The carbonation reaction was mechanically driven via reactive ball milling. The carbonation rate was determined by monitoring the CO2 pressure inside [...] Read more.
The carbonation behavior of calcium-containing sorbents, CaO and Ca(OH)2, was investigated under pressurized CO2 at nominal room temperature. The carbonation reaction was mechanically driven via reactive ball milling. The carbonation rate was determined by monitoring the CO2 pressure inside the sealed milling jar. Two different versions of CaO were fabricated as starting materials. The addition of citric acid in CaO synthesis resulted in a significant increase in sorbent surface area, bringing up the conversion of CO2 from 18% to 41% after 3 h of reactive milling. The hydroxide formation from these two oxides closed the surface area gap. Nevertheless, we found that hydroxides had a higher initial carbonation rate and greater final CO2 uptake than their oxide counterparts. However, the formation of byproduct water limited the further carbonation of Ca(OH)2. When we added a controlled amount of water to the CaO-containing milling jar, the highest carbonation rate and most extensive CO2 uptake were attained due to the in situ formation of reactive Ca(OH)2 nanoparticles. We saw CaCO3 X-ray diffraction peaks only when Ca(OH)2 was involved in this low-temperature carbonation, indicating that the grain growth of CaCO3 is easier on the Ca(OH)2 surface than on the CaO surface. We used the Friedman isoconversional method to calculate the effective activation energy of decarbonation for the high surface area CaO sorbent milled with water. The average effective activation energy was found to be about 72 kJ mol−1, and its magnitude started to decrease significantly from 50% sorbent regeneration. The drastic change of the effective activation energy during decarbonation suggests that CaCO3, formed at nominal room temperature by reactive milling under pressurized CO2, should undergo a more drastic morphology change than the typical thermally carbonated CaCO3. Full article
(This article belongs to the Special Issue Recent Advancements of Metal Oxide in Catalysis)
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10 pages, 1163 KiB  
Article
Thermodynamics of Ag(I) Complex Formations with 2-Mercaptoimidazole in Water−Dimethyl Sulfoxide Solvents
by Surayo Bobosaidzoda, Anjuman Sodatdinova, Khazon Akimbekova, Diana Alister, Evgeniy Molchanov, Yuriy Marfin, Tatyana Usacheva and Safarmamad Safarmamadzoda
Inorganics 2023, 11(5), 199; https://doi.org/10.3390/inorganics11050199 - 3 May 2023
Cited by 2 | Viewed by 1402
Abstract
The stability of coordination compounds of metal ions with ligands is of fundamental importance for elaborating upon practical sensors for the detection and quantification of metal ions in environmental samples. In this work, the stability constants of silver(I) complexes with 2-mercaptoimidazole (2MI) in [...] Read more.
The stability of coordination compounds of metal ions with ligands is of fundamental importance for elaborating upon practical sensors for the detection and quantification of metal ions in environmental samples. In this work, the stability constants of silver(I) complexes with 2-mercaptoimidazole (2MI) in a mixed water–dimethyl sulfoxide (DMSO) solvent were determined at 298.15 K and 308.15 K. It was found that with increasing temperature, the stability of the complexes decreases. The dependence of lgβ1 on the water−DMSO solvent compositions has its minimum at a concentration of dimethyl sulfoxide of 0.1 mol. fr. To explain the effect of the solvent, the solvation characteristics of the reagents were analyzed. In this regard, the 2MI Gibbs energy of transfer from water to aqueous dimethyl sulfoxide solvents was determined, and the influence of the aqueous DMSO solvent on the thermodynamics of 2MI protonation was analyzed. The stabilization of the silver ion and 2MI during the transition from water to a water–DMSO solvent makes a negative contribution to the change in the Gibbs energy of complexation, while the solvation of a complex particle promotes the complex formation. As a result, the Gibbs energy transfer values are slightly increased. The results of these thermodynamic studies could be useful for the development of sensor materials based on mercaptoimidazoles. Full article
(This article belongs to the Special Issue Chemical Sensors of Inorganic Cations and Anions)
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20 pages, 3224 KiB  
Article
Pt(II) Complexes with a Novel Pincer N^C^N Ligand: Synthesis, Characterization, and Photophysics
by Evgeniia E. Luneva, Daria O. Kozina, Anna V. Mozzhukhina, Vitaly V. Porsev, Anastasia I. Solomatina and Sergey P. Tunik
Inorganics 2023, 11(5), 198; https://doi.org/10.3390/inorganics11050198 - 3 May 2023
Viewed by 2288
Abstract
A series of new platinum square planar complexes [Pt(NCN)L]+/0 with the pincer N^C^N cyclometallated ligand (NC(H)N = 1,3-bis(1-phenyl-1H-phenanthro[9,10-d]imidazol-2-yl)benzene) containing the following L: Cl−, acetonitrile, pyridine, dimethylaminopyridine, 2,6-dimethylphenylisocyanide, has been synthesized. Application of bridging acetate ion as L ligand allowed [...] Read more.
A series of new platinum square planar complexes [Pt(NCN)L]+/0 with the pincer N^C^N cyclometallated ligand (NC(H)N = 1,3-bis(1-phenyl-1H-phenanthro[9,10-d]imidazol-2-yl)benzene) containing the following L: Cl−, acetonitrile, pyridine, dimethylaminopyridine, 2,6-dimethylphenylisocyanide, has been synthesized. Application of bridging acetate ion as L ligand allowed obtaining a binuclear [Pt(NCN)]2OOCCH3 complex. The bulky and rigid structure of N^C^N-ligand provokes instability of its pincer coordination that makes possible transformation of the molecular architecture to give a heteronuclear complex with the Pt-Ag-Pt coordination core. The composition and structure of the obtained compounds were characterized in solution and in the solid state using ESI mass-spectrometry, NMR spectroscopy, elemental analysis, and single-crystal XRD crystallography. The complexes luminesce in solid state, solution, and in polymeric matrix demonstrating moderate to bright emission at ca. 550 nm with quantum yields up to 22% and lifetime of excited state up to 22 µs. TD DFT computational approach together with analysis of the photophysical properties in different media reveals the predominant ligand-centered 3IL nature of the radiative excited state localized at the N^C^N-ligand. The ancillary ligand L demonstrates a minor influence on the energy of emission but affects dramatically emission efficiency and lifetime. The chloride complex displays dual (fluorescence and phosphorescent) luminescence due to labile coordination of an N-coordinated functionality that produces a dangling aromatic fragment, which gives emission from a singlet excited state. Full article
(This article belongs to the Special Issue Light Emitting Metal Complexes)
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28 pages, 6790 KiB  
Review
Graphene-Based Electrochemical Nano-Biosensors for Detection of SARS-CoV-2
by Joydip Sengupta and Chaudhery Mustansar Hussain
Inorganics 2023, 11(5), 197; https://doi.org/10.3390/inorganics11050197 - 1 May 2023
Cited by 13 | Viewed by 3732
Abstract
COVID-19, a viral respiratory illness, is caused by Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2), which was first identified in Wuhan, China, in 2019 and rapidly spread worldwide. Testing and isolation were essential to control the virus’s transmission due to the severity [...] Read more.
COVID-19, a viral respiratory illness, is caused by Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2), which was first identified in Wuhan, China, in 2019 and rapidly spread worldwide. Testing and isolation were essential to control the virus’s transmission due to the severity of the disease. In this context, there is a global interest in the feasibility of employing nano-biosensors, especially those using graphene as a key material, for the real-time detection of the virus. The exceptional properties of graphene and the outstanding performance of nano-biosensors in identifying various viruses prompted a feasibility check on this technology. This paper focuses on the recent advances in using graphene-based electrochemical biosensors for sensing the SARS-CoV-2 virus. Specifically, it reviews various types of electrochemical biosensors, including amperometric, potentiometric, and impedimetric biosensors, and discusses the current challenges associated with biosensors for SARS-CoV-2 detection. The conclusion of this review discusses future directions in the field of electrochemical biosensors for SARS-CoV-2 detection, underscoring the importance of continued research and development in this domain. Full article
(This article belongs to the Special Issue Electrochemical Study of Nanocarbon Based Materials)
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12 pages, 7888 KiB  
Article
Oxygen-Ion and Proton Transport of Origin and Ca-Doped La2ZnNdO5.5 Materials
by Ksenia Belova, Anastasia Egorova, Svetlana Pachina, Irina Animitsa and Dmitry Medvedev
Inorganics 2023, 11(5), 196; https://doi.org/10.3390/inorganics11050196 - 1 May 2023
Viewed by 1594
Abstract
Oxygen-ionic and proton-conducting oxides are widely studied materials for their application in various electrochemical devices such as solid oxide fuel cells and electrolyzers. Rare earth oxides are known as a class of ionic conductors. In this paper, La2ZnNdO5.5 and its [...] Read more.
Oxygen-ionic and proton-conducting oxides are widely studied materials for their application in various electrochemical devices such as solid oxide fuel cells and electrolyzers. Rare earth oxides are known as a class of ionic conductors. In this paper, La2ZnNdO5.5 and its Ca-doped derivatives La2Nd0.9Ca0.1ZnO5.45 and La2ZnNd0.9Ca0.1O5.45 were obtained by a solid-state reaction route. Phase composition, lattice parameters, and hydration capability were investigated by X-ray diffraction and thermogravimetric analyses. The conductivities of these materials were measured by the electrochemical impedance spectroscopy technique in dry (pH2O = 3.5 × 10−5 atm) and wet (pH2O = 2 × 10−2 atm) air. All phases crystallized in a trigonal symmetry with P3m1 space group. The conductivity difference between undoped and calcium-doped samples is more than two orders of magnitude due to the appearance of oxygen vacancies during acceptor doping, which are responsible for a higher ionic conductivity. The La2Nd0.9Ca0.1ZnO5.45 sample shows the highest conductivity of about 10−3 S∙cm−1 at 650 °C. The Ca-doped phases are capable of reversible water uptake, confirming their proton-conducting nature. Full article
(This article belongs to the Special Issue Layered Perovskites: Synthesis, Properties and Structures)
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17 pages, 2159 KiB  
Article
Novel Copper(II) Complexes with N4,S-Diallylisothiosemicarbazones as Potential Antibacterial/Anticancer Drugs
by Vasilii Graur, Irina Usataia, Ianina Graur, Olga Garbuz, Paulina Bourosh, Victor Kravtsov, Carolina Lozan-Tirsu, Greta Balan, Valeriu Fala and Aurelian Gulea
Inorganics 2023, 11(5), 195; https://doi.org/10.3390/inorganics11050195 - 30 Apr 2023
Cited by 4 | Viewed by 1752
Abstract
The six new copper(II) coordination compounds [Cu(HL1)Cl2] (1), [Cu(HL1)Br2] (2), [Cu(H2O)(L1)(CH3COO)]·1.75H2O (3), [Cu(HL2)Cl2] (4), [Cu(HL [...] Read more.
The six new copper(II) coordination compounds [Cu(HL1)Cl2] (1), [Cu(HL1)Br2] (2), [Cu(H2O)(L1)(CH3COO)]·1.75H2O (3), [Cu(HL2)Cl2] (4), [Cu(HL2)Br2] (5), [Cu(H2O)(L2)(CH3COO)] (6) were synthesized with 2-formyl- and 2-acetylpyridine N4,S-diallylisothiosemicarbazones (HL1 and HL2). The new isothiosemicarbazones were characterized by NMR, FTIR spectroscopy, and X-ray crystallography ([H2L2]I). All copper(II) coordination compounds were characterized by elemental analysis, FTIR spectroscopy, and molar conductivity of their 1mM methanol solutions. Furthermore, the crystal structure of complex 3 was determined using single-crystal X-ray diffraction analysis. The studied complexes manifest antibacterial and antifungal activities, that in many cases are close to the activity of medical drugs used in this area, and in some cases even exceed them. The complexes 4 and 5 showed the highest indexes of selectivity (280 and 154) and high antiproliferative activity against BxPC-3 cell lines that surpass the activity of Doxorubicin. The complexes 1–3 also manifest antioxidant activities against cation radicals ABTS•+ that are close to that of trolox, the antioxidant agent used in medicine. Full article
(This article belongs to the Special Issue Editorial Board Members’ Collection Series in “Bioinorganic Chemistry of Copper”)
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23 pages, 11040 KiB  
Review
Co(III) Intermediates in Cobalt-Catalyzed, Bidentate Chelation Assisted C(sp2)-H Functionalizations
by Aleksandrs Cizikovs and Liene Grigorjeva
Inorganics 2023, 11(5), 194; https://doi.org/10.3390/inorganics11050194 - 29 Apr 2023
Cited by 7 | Viewed by 2195
Abstract
The C-H bond activation and functionalization is a powerful tool that provides efficient access to various organic molecules. The cobalt-catalyzed oxidative C-H bond activation and functionalization has earned enormous interest over the past two decades. Since then, a wide diversity of synthetic protocols [...] Read more.
The C-H bond activation and functionalization is a powerful tool that provides efficient access to various organic molecules. The cobalt-catalyzed oxidative C-H bond activation and functionalization has earned enormous interest over the past two decades. Since then, a wide diversity of synthetic protocols have been published for C-C, C-Het, and C-Hal bond formation reactions. To gain some insights into the reaction mechanism, the authors performed a series of experiments and collected evidence. Several groups have successfully isolated reactive Co(III) intermediates to elucidate the reaction mechanism. In this review, we will summarize information concerning the isolated and synthesized Co(III) intermediates in cobalt-catalyzed, bidentate chelation assisted C-H bond functionalization and their reactivity based on the current knowledge about the general reaction mechanism. Full article
(This article belongs to the Special Issue Recent Highlights Using Cobalt Catalysis)
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