Pub Date : 2023-09-05DOI: 10.3390/inorganics11090361
R. E. Yagovitin, D. Tsvetkov, I. Ivanov, D. Malyshkin, V. Sereda, A. Zuev
The differential scanning calorimetry study showed that the double perovskite HoBaCo2O6-δ (HBC), depending on its oxygen content, undergoes three phase transitions in the temperature range 298–773 K. Their origin was tentatively explained using the relevant literature data. For the single-phase tetragonal HBC, the oxygen nonstoichiometry dependences on the oxygen partial pressure were investigated by thermogravimetric and flow reactor methods in the intermediate-temperature range of 573–773 K. The proposed defect structure of HBC was successfully verified using the obtained data on its oxygen nonstoichiometry combined with those reported earlier. As a result, the values of the thermodynamic parameters (∆Hi∘, ∆Si∘) of the defect reactions proceeding in HBC were determined. The defect structure of HBC was shown to be similar to that of YBaCo2O6-δ (YBC) likely due to similar ionic radii of Ho3+ and Y3+.
{"title":"Phase Behavior and Defect Structure of HoBaCo2O6-δ","authors":"R. E. Yagovitin, D. Tsvetkov, I. Ivanov, D. Malyshkin, V. Sereda, A. Zuev","doi":"10.3390/inorganics11090361","DOIUrl":"https://doi.org/10.3390/inorganics11090361","url":null,"abstract":"The differential scanning calorimetry study showed that the double perovskite HoBaCo2O6-δ (HBC), depending on its oxygen content, undergoes three phase transitions in the temperature range 298–773 K. Their origin was tentatively explained using the relevant literature data. For the single-phase tetragonal HBC, the oxygen nonstoichiometry dependences on the oxygen partial pressure were investigated by thermogravimetric and flow reactor methods in the intermediate-temperature range of 573–773 K. The proposed defect structure of HBC was successfully verified using the obtained data on its oxygen nonstoichiometry combined with those reported earlier. As a result, the values of the thermodynamic parameters (∆Hi∘, ∆Si∘) of the defect reactions proceeding in HBC were determined. The defect structure of HBC was shown to be similar to that of YBaCo2O6-δ (YBC) likely due to similar ionic radii of Ho3+ and Y3+.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44838964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.3390/inorganics11090360
Yuepeng Hei, Zuojun Lu, Claudia Li, Jian Song, Bo Meng, Naitao Yang, S. Kawi, J. Sunarso, X. Tan, Shaomin Liu
Partial oxidation of methane (POM) is a prominent pathway for syngas production, wherein the hydrogen in syngas product can be recovered directly from the reaction system using a hydrogen (H2)-permeable membrane. Enhancing the efficiency of this H2 separation process is a current major challenge. In this study, Ce0.8Y0.2O2-δ-BaCe0.8Y0.2O3-δ (YDC-BCY) hollow fiber (HF) membranes were developed and characterized for their H2 permeation fluxes. Firstly, YDC and BCY ceramic powders were synthesized using the sol-gel method, followed by the fabrication of YDC-BCY dual-phase ceramic HF membranes using a combined phase inversion–sintering process. Characterization using SEM, powder XRD, EDS, and electrical conductivity tests confirmed the phases of the prepared powders and HF membranes. Well-structured YDC and BCY powders with uniform particle sizes were obtained after calcination at 900 °C. With the addition of 1 wt.% Co2O3 as a sintering aid, the YDC-BCY dual-phase HF membrane achieved densification after sintering at 1500 °C. Subsequently, the influences of sweep gas composition and temperature on the hydrogen permeation of the YDC-BCY HF membranes with YDC/BCY molar ratios of 2:1, 3:1, and 4:1 were investigated. At 1000 °C and a sweep-gas flow rate of 120 mL·min−1, the YDC-BCY HF membrane with a YDC/BCY molar ratio of 4:1 exhibited a peak hydrogen flux of 0.30 mL·min−1 cm−2. There is significant potential for improving the hydrogen permeation of dual-phase ceramic membranes, with future efforts aimed at reducing dense layer thickness and enhancing the membrane material’s electronic and proton conductivities.
{"title":"Ce0.8Y0.2O2-δ-BaCe0.8Y0.2O3-δ Dual-Phase Hollow Fiber Membranes for Hydrogen Separation","authors":"Yuepeng Hei, Zuojun Lu, Claudia Li, Jian Song, Bo Meng, Naitao Yang, S. Kawi, J. Sunarso, X. Tan, Shaomin Liu","doi":"10.3390/inorganics11090360","DOIUrl":"https://doi.org/10.3390/inorganics11090360","url":null,"abstract":"Partial oxidation of methane (POM) is a prominent pathway for syngas production, wherein the hydrogen in syngas product can be recovered directly from the reaction system using a hydrogen (H2)-permeable membrane. Enhancing the efficiency of this H2 separation process is a current major challenge. In this study, Ce0.8Y0.2O2-δ-BaCe0.8Y0.2O3-δ (YDC-BCY) hollow fiber (HF) membranes were developed and characterized for their H2 permeation fluxes. Firstly, YDC and BCY ceramic powders were synthesized using the sol-gel method, followed by the fabrication of YDC-BCY dual-phase ceramic HF membranes using a combined phase inversion–sintering process. Characterization using SEM, powder XRD, EDS, and electrical conductivity tests confirmed the phases of the prepared powders and HF membranes. Well-structured YDC and BCY powders with uniform particle sizes were obtained after calcination at 900 °C. With the addition of 1 wt.% Co2O3 as a sintering aid, the YDC-BCY dual-phase HF membrane achieved densification after sintering at 1500 °C. Subsequently, the influences of sweep gas composition and temperature on the hydrogen permeation of the YDC-BCY HF membranes with YDC/BCY molar ratios of 2:1, 3:1, and 4:1 were investigated. At 1000 °C and a sweep-gas flow rate of 120 mL·min−1, the YDC-BCY HF membrane with a YDC/BCY molar ratio of 4:1 exhibited a peak hydrogen flux of 0.30 mL·min−1 cm−2. There is significant potential for improving the hydrogen permeation of dual-phase ceramic membranes, with future efforts aimed at reducing dense layer thickness and enhancing the membrane material’s electronic and proton conductivities.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46176781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-30DOI: 10.3390/inorganics11090359
Micaela Richezzi, Sharon Signorella, C. Palopoli, N. Pellegri, C. Hureau, S. Signorella
In low-molecular-weight Mn superoxide dismutase (SOD) mimics, the ligand plays a key role in tuning the reactivity of the metal center with O2•−. We used three ligands differing in their donor sites, flexibility and/or charge, to compare the redox properties and SOD activity of the resulting Mn complexes: 1,3-bis[(pyridin-2-ylmethyl)(propargyl)amino]propane (pypapn), 1,3-bis(pyridin-2-ylmethyleneamino)propane (py2pn) and 1,4-bis(salicylidenamino)butane (H2salbn). These ligands afford Mn complexes that, in aqueous solution, exist as mononuclear species [Mn(II)(pypapn)(H2O)2]2+, [Mn(II)(py2pn)(H2O)2]2+ and [Mn(III)(salbn)(H2O)2]+. The relative reactivity of these compounds with O2•− at pH 7.8, [Mn(pypapn)(H2O)2]2+ > [Mn(salbn)(H2O)2]+ > [Mn(py2pn)(H2O)2]2+, is independent of the redox potential but strongly depends on the ligand flexibility which becomes a critical feature when the reaction occurs through an inner-sphere electron-transfer mechanism. Immobilization was used to isolate and protect the catalyst from dissociation or dimerization during catalysis. [Mn(pypapn)(H2O)2]2+, with the alkyne group, was covalently grafted to azide functionalized mesoporous silica through click chemistry, while [Mn(py2pn)(solv)2]2+ and [Mn(salbn)(solv)2]+ were encapsulated in SBA-15 mesoporous silica through ionic exchange. The retention or enhancement of the SOD activity and the improved stability of the covalently attached catalyst and the doubly charged complex encapsulated in the silica pores, make them suitable for use in aqueous media.
{"title":"The Critical Role of Ligand Flexibility on the Activity of Free and Immobilized Mn Superoxide Dismutase Mimics","authors":"Micaela Richezzi, Sharon Signorella, C. Palopoli, N. Pellegri, C. Hureau, S. Signorella","doi":"10.3390/inorganics11090359","DOIUrl":"https://doi.org/10.3390/inorganics11090359","url":null,"abstract":"In low-molecular-weight Mn superoxide dismutase (SOD) mimics, the ligand plays a key role in tuning the reactivity of the metal center with O2•−. We used three ligands differing in their donor sites, flexibility and/or charge, to compare the redox properties and SOD activity of the resulting Mn complexes: 1,3-bis[(pyridin-2-ylmethyl)(propargyl)amino]propane (pypapn), 1,3-bis(pyridin-2-ylmethyleneamino)propane (py2pn) and 1,4-bis(salicylidenamino)butane (H2salbn). These ligands afford Mn complexes that, in aqueous solution, exist as mononuclear species [Mn(II)(pypapn)(H2O)2]2+, [Mn(II)(py2pn)(H2O)2]2+ and [Mn(III)(salbn)(H2O)2]+. The relative reactivity of these compounds with O2•− at pH 7.8, [Mn(pypapn)(H2O)2]2+ > [Mn(salbn)(H2O)2]+ > [Mn(py2pn)(H2O)2]2+, is independent of the redox potential but strongly depends on the ligand flexibility which becomes a critical feature when the reaction occurs through an inner-sphere electron-transfer mechanism. Immobilization was used to isolate and protect the catalyst from dissociation or dimerization during catalysis. [Mn(pypapn)(H2O)2]2+, with the alkyne group, was covalently grafted to azide functionalized mesoporous silica through click chemistry, while [Mn(py2pn)(solv)2]2+ and [Mn(salbn)(solv)2]+ were encapsulated in SBA-15 mesoporous silica through ionic exchange. The retention or enhancement of the SOD activity and the improved stability of the covalently attached catalyst and the doubly charged complex encapsulated in the silica pores, make them suitable for use in aqueous media.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47180347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-30DOI: 10.3390/inorganics11090357
Hessa H. Al-Rasheed, Sarah A. AL-khamis, A. El‐Faham, A. Barakat, Alexandra M. Z. Slawin, J. Woollins, S. Soliman
The unexpected tetranuclear [Cu4(DPPT)2Cl6] complex was obtained by self-assembly of CuCl2.2H2O and (E)-2,4-di(piperidin-1-yl)-6-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)-1,3,5-triazine, (HDPPT) in ethanol. In this tetranuclear [Cu4(DPPT)2Cl6] complex, the organic ligand acts as mononegative chelate bridging two crystallographically independent Cu(II) sites. The DPPT− anion acts as a bidentate ligand with respect to Cu(1), while it is a tridentate for Cu(2). The Cu(1)N2Cl3 and Cu(2)N3Cl spheres have square pyramidal and square planar coordination geometries with some distortion, respectively. Two of the chloride ions coordinating the Cu(1) are bridging between two crystallographically related Cu(1) sites connecting two [Cu2(DPPT)Cl3] units together, leading to the tetranuclear formula [Cu4(DPPT)2Cl6]. The packing of the [Cu4(DPPT)2Cl6] complex is dominated by C-H…Cl contacts, leading to one-dimensional hydrogen-bond polymeric structure. According to Hirshfeld surface analysis of molecular packing, the non-covalent interactions H…H, Cl…H, Cl…C, C…H, and N…H are the most significant. Their percentages are 52.8, 19.0, 3.2, 7.7, and 9.7%, respectively. Antimicrobial assessment showed good antifungal activity of the Cu(II) complex against A. fumigatus and C. albicans compared to Ketoconazole as positive control. Moreover, the [Cu4(DPPT)2Cl6] complex has higher activity against Gram-positive bacteria than Gentamycin as positive control. The opposite was observed when testing the tetranuclear [Cu4(DPPT)2Cl6] complex against the Gram-negative bacteria.
{"title":"Synthesis, X-ray Structure, Hirshfeld Surface Analysis and Antimicrobial Assessment of Tetranuclear s-Triazine Hydrazine Schiff Base Ligand","authors":"Hessa H. Al-Rasheed, Sarah A. AL-khamis, A. El‐Faham, A. Barakat, Alexandra M. Z. Slawin, J. Woollins, S. Soliman","doi":"10.3390/inorganics11090357","DOIUrl":"https://doi.org/10.3390/inorganics11090357","url":null,"abstract":"The unexpected tetranuclear [Cu4(DPPT)2Cl6] complex was obtained by self-assembly of CuCl2.2H2O and (E)-2,4-di(piperidin-1-yl)-6-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)-1,3,5-triazine, (HDPPT) in ethanol. In this tetranuclear [Cu4(DPPT)2Cl6] complex, the organic ligand acts as mononegative chelate bridging two crystallographically independent Cu(II) sites. The DPPT− anion acts as a bidentate ligand with respect to Cu(1), while it is a tridentate for Cu(2). The Cu(1)N2Cl3 and Cu(2)N3Cl spheres have square pyramidal and square planar coordination geometries with some distortion, respectively. Two of the chloride ions coordinating the Cu(1) are bridging between two crystallographically related Cu(1) sites connecting two [Cu2(DPPT)Cl3] units together, leading to the tetranuclear formula [Cu4(DPPT)2Cl6]. The packing of the [Cu4(DPPT)2Cl6] complex is dominated by C-H…Cl contacts, leading to one-dimensional hydrogen-bond polymeric structure. According to Hirshfeld surface analysis of molecular packing, the non-covalent interactions H…H, Cl…H, Cl…C, C…H, and N…H are the most significant. Their percentages are 52.8, 19.0, 3.2, 7.7, and 9.7%, respectively. Antimicrobial assessment showed good antifungal activity of the Cu(II) complex against A. fumigatus and C. albicans compared to Ketoconazole as positive control. Moreover, the [Cu4(DPPT)2Cl6] complex has higher activity against Gram-positive bacteria than Gentamycin as positive control. The opposite was observed when testing the tetranuclear [Cu4(DPPT)2Cl6] complex against the Gram-negative bacteria.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44137210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-30DOI: 10.3390/inorganics11090358
M. Soriano-Ursúa
The role of boron-containing compounds (BCCs) in medicine is growing [...]
含硼化合物（BCCs）在医学中的作用越来越大〔…〕
{"title":"Boron Applications in Prevention, Diagnosis and Therapy for High Global Burden Diseases","authors":"M. Soriano-Ursúa","doi":"10.3390/inorganics11090358","DOIUrl":"https://doi.org/10.3390/inorganics11090358","url":null,"abstract":"The role of boron-containing compounds (BCCs) in medicine is growing [...]","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48215487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-29DOI: 10.3390/inorganics11090356
Christina Stamou, Eleftheria Barouni, J. Plakatouras, M. Sigalas, C. Raptopoulou, V. Psycharis, E. Bakalbassis, S. Perlepes
In an attempt to fill in the empty Zn position in the “Periodic Table” of 1-methylbenzotriazole (Mebta), reactions between Zn(II) sources and this ligand were carried out. The detailed synthetic studies provided access to complexes [ZnX2(Mebta)2] (X = Cl, 1; X = Br, 3; X = I, 4), (MebtaH)2[ZnCl4] (2), tet-[Zn(NO3)2(Mebta)2] (5), oct-[Zn(NO3)2(Mebta)2] (6), and [Zn(Mebta)4](Y)2 [Y = ClO4, 7; Y = PF6, 8]. Solid-state thermal decomposition of 2 leads to 1 in quantitative yield. The structures of 3, 4, 5, 6, and 7 were determined by single-crystal crystallography. The structures of the remaining complexes were proposed based on spectroscopic evidence. In all compounds, Mebta behaves as monodentate ligand using the nitrogen of the position 3 as donor. Complexes 1–4, 7, and 8 are tetrahedral. Complexes 5 and 6 are isostoichiometric and their preparation in pure forms depends on the reaction conditions; in the former the ZnII atom has a tetrahedral geometry, whereas in the latter the metal ion is octahedral. This case of rare isomerism arises from the monodentate (in 5) vs. bidentate (in 6) coordination of the nitrato groups. Extensive π–π stacking interactions and non-classical H bonds build interesting 3D architectures in the structurally characterized complexes. The compounds were characterized by IR, far-IR, and Raman spectroscopies in the solid state, and the data were interpreted in terms of the structures (known or proposed) of the complexes and the coordination modes of the organic and inorganic ligands involved. The solid-state structures of the complexes are not retained in solution, as proven by NMR (1H, 13C[1H]) spectroscopy and molar conductivity data. The thermal decomposition study of 1 and 3 leads to stable intermediates with 1:1 stoichiometry, i.e., ZnX2(Mebta). Based on far-IR spectra, polymeric tetrahedral structures are possible with simultaneous presence of terminal and bridging X− groups. Liquid-phase ab initio (MP2) and gas-phase DFT calculations, performed on Mebta and the nitrato complexes, respectively, shed light on the tendency of Mebta for N3-coordination, and the existence and relative stabilities of 5 and 6.
{"title":"The “Periodic Table” of 1-methylbenzotriazole: Zinc(II) Complexes","authors":"Christina Stamou, Eleftheria Barouni, J. Plakatouras, M. Sigalas, C. Raptopoulou, V. Psycharis, E. Bakalbassis, S. Perlepes","doi":"10.3390/inorganics11090356","DOIUrl":"https://doi.org/10.3390/inorganics11090356","url":null,"abstract":"In an attempt to fill in the empty Zn position in the “Periodic Table” of 1-methylbenzotriazole (Mebta), reactions between Zn(II) sources and this ligand were carried out. The detailed synthetic studies provided access to complexes [ZnX2(Mebta)2] (X = Cl, 1; X = Br, 3; X = I, 4), (MebtaH)2[ZnCl4] (2), tet-[Zn(NO3)2(Mebta)2] (5), oct-[Zn(NO3)2(Mebta)2] (6), and [Zn(Mebta)4](Y)2 [Y = ClO4, 7; Y = PF6, 8]. Solid-state thermal decomposition of 2 leads to 1 in quantitative yield. The structures of 3, 4, 5, 6, and 7 were determined by single-crystal crystallography. The structures of the remaining complexes were proposed based on spectroscopic evidence. In all compounds, Mebta behaves as monodentate ligand using the nitrogen of the position 3 as donor. Complexes 1–4, 7, and 8 are tetrahedral. Complexes 5 and 6 are isostoichiometric and their preparation in pure forms depends on the reaction conditions; in the former the ZnII atom has a tetrahedral geometry, whereas in the latter the metal ion is octahedral. This case of rare isomerism arises from the monodentate (in 5) vs. bidentate (in 6) coordination of the nitrato groups. Extensive π–π stacking interactions and non-classical H bonds build interesting 3D architectures in the structurally characterized complexes. The compounds were characterized by IR, far-IR, and Raman spectroscopies in the solid state, and the data were interpreted in terms of the structures (known or proposed) of the complexes and the coordination modes of the organic and inorganic ligands involved. The solid-state structures of the complexes are not retained in solution, as proven by NMR (1H, 13C[1H]) spectroscopy and molar conductivity data. The thermal decomposition study of 1 and 3 leads to stable intermediates with 1:1 stoichiometry, i.e., ZnX2(Mebta). Based on far-IR spectra, polymeric tetrahedral structures are possible with simultaneous presence of terminal and bridging X− groups. Liquid-phase ab initio (MP2) and gas-phase DFT calculations, performed on Mebta and the nitrato complexes, respectively, shed light on the tendency of Mebta for N3-coordination, and the existence and relative stabilities of 5 and 6.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47612636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-29DOI: 10.3390/inorganics11090355
M. Esaifan, Ahmed Al-Mobydeen, A. Al-Masri, Abdelmnim M. Altwaiq, B. Al-Saqarat, Wadah Mahmoud, A. Hamaideh, I. Moosa, I. Hamadneh, E. AlShamaileh
Aluminum oxide production from aluminum filings, which are a byproduct of several industrial machining processes and cannot be recycled to attain bulk aluminum (Al), is vital due to its wide use in scientific research and industry. The goal of this paper is to produce ultrafine and down-to-the-nanoscale alumina powder (Al2O3), starting from a waste Al filings. The microstructure and composition of the starting Al used were investigated using scanning electron microscopy (SEM), which was equipped with an attached energy dispersive spectrometer (EDS) unit. The results of this investigation confirmed that the starting Al was mainly Al–Mg alloy. Al2O3 was produced using two routes: The first involved the burning of aluminum hydroxide Al(OH)3 that was precipitated from aluminum chloride solution (AlCl3) resulting from dissolving the Al filings in 2M HCl. The second route involved direct precipitation as a reaction product of aluminum chloride with sodium carbonate solution. The Al2O3 produced using both routes, as well as the intermediate product Al(OH)3, were studied by SEM. The results demonstrate that the nanoscale range size was reached after milling of the produced Al2O3. Following thorough washing with distilled water, the EDS and the XRD techniques confirmed the formation of Al2O3, with no residual salt detected. The EDS results showed that the ratios of Al and O in the produced Al2O3 were about 96% of the ideal compound ratios. The XRD analysis also revealed the amorphous structure of the standard and the produced Al(OH)3, whereas the phases of the produced Al2O3 were either crystalline or amorphous. In our study, the Al2O3 percentage yield was about 77%, and this value obviously depends on the percentage of Al dross in the original Al filings. Overall, this research provides a novel contribution to the production of alumina powder in the nano-range starting from an aluminum filings byproduct, thereby reducing the dependence on known sources of aluminum.
{"title":"Synthesis of Nanostructured Alumina from Byproduct Aluminum Filings: Production and Characterization","authors":"M. Esaifan, Ahmed Al-Mobydeen, A. Al-Masri, Abdelmnim M. Altwaiq, B. Al-Saqarat, Wadah Mahmoud, A. Hamaideh, I. Moosa, I. Hamadneh, E. AlShamaileh","doi":"10.3390/inorganics11090355","DOIUrl":"https://doi.org/10.3390/inorganics11090355","url":null,"abstract":"Aluminum oxide production from aluminum filings, which are a byproduct of several industrial machining processes and cannot be recycled to attain bulk aluminum (Al), is vital due to its wide use in scientific research and industry. The goal of this paper is to produce ultrafine and down-to-the-nanoscale alumina powder (Al2O3), starting from a waste Al filings. The microstructure and composition of the starting Al used were investigated using scanning electron microscopy (SEM), which was equipped with an attached energy dispersive spectrometer (EDS) unit. The results of this investigation confirmed that the starting Al was mainly Al–Mg alloy. Al2O3 was produced using two routes: The first involved the burning of aluminum hydroxide Al(OH)3 that was precipitated from aluminum chloride solution (AlCl3) resulting from dissolving the Al filings in 2M HCl. The second route involved direct precipitation as a reaction product of aluminum chloride with sodium carbonate solution. The Al2O3 produced using both routes, as well as the intermediate product Al(OH)3, were studied by SEM. The results demonstrate that the nanoscale range size was reached after milling of the produced Al2O3. Following thorough washing with distilled water, the EDS and the XRD techniques confirmed the formation of Al2O3, with no residual salt detected. The EDS results showed that the ratios of Al and O in the produced Al2O3 were about 96% of the ideal compound ratios. The XRD analysis also revealed the amorphous structure of the standard and the produced Al(OH)3, whereas the phases of the produced Al2O3 were either crystalline or amorphous. In our study, the Al2O3 percentage yield was about 77%, and this value obviously depends on the percentage of Al dross in the original Al filings. Overall, this research provides a novel contribution to the production of alumina powder in the nano-range starting from an aluminum filings byproduct, thereby reducing the dependence on known sources of aluminum.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45722382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-29DOI: 10.3390/inorganics11090354
I. Alnaser, A. Fouly, M. Aijaz, J. A. Mohammed, M. B. Elsheniti, Sameh A. Ragab, H. S. Abdo
This research work highlights the tribomechanical investigations of using a low loading fraction of two ceramics combinations, Alumina (Al2O3) and Silicon Carbide (SiC) as reinforcement for Low-density Polyethylene (LDPE) matrix. The hybrid additives with different weight percentages (0.1 + 0.1, 0.25 + 0.25 and 0.5 + 0.5 wt%) were mixed with LDPE matrix and the degree of homogeneity was controlled using double-screw extruder prior to fabricating the composite samples via the injection molding machine. The nanoparticles fillers were characterized by field emission scanning electron microscope (FESEM), EDX and particle size analyzer to check its morphology, composition and size distribution. Thermogravimetric analyzer (TGA) and melting flow index (MFI) were performed for the fabricated nanocomposites samples. The mechanical properties of the nanocomposite were evaluated by performing tensile test, bending test and Shore-D hardness test, while the tribological performance was investigated using a ball on desk apparatus under different applied loads and sliding times. Moreover, in order to confirm the load-carrying capability of the composite, contact stresses was measured via finite element model using ANSYS software. The results show that the incorporation of low fraction hybrid ceramic nanoparticles can contributed positively in the tribological and mechanical properties. Based on the experimental results, the maximum improvement in the tensile strength was 5.38%, and 8.15% for hardness LDPE with 0.5 Al2O3 and 0.5 SiC, while the lowest coefficient of friction was noticed under normal load of 10 N, which was approximately 12.5% for the same composition. The novel approach of incorporating low fraction hybrid ceramic nanoparticles as reinforcement for LDPE matrix is investigated, highlighting their positive contributions to the tribological and mechanical properties of the resulting nanocomposites.
{"title":"Enhancing the Tribo-Mechanical Performance of LDPE Nanocomposites Utilizing Low Loading Fraction Al2O3/SiC Hybrid Nanostructured Oxide Fillers","authors":"I. Alnaser, A. Fouly, M. Aijaz, J. A. Mohammed, M. B. Elsheniti, Sameh A. Ragab, H. S. Abdo","doi":"10.3390/inorganics11090354","DOIUrl":"https://doi.org/10.3390/inorganics11090354","url":null,"abstract":"This research work highlights the tribomechanical investigations of using a low loading fraction of two ceramics combinations, Alumina (Al2O3) and Silicon Carbide (SiC) as reinforcement for Low-density Polyethylene (LDPE) matrix. The hybrid additives with different weight percentages (0.1 + 0.1, 0.25 + 0.25 and 0.5 + 0.5 wt%) were mixed with LDPE matrix and the degree of homogeneity was controlled using double-screw extruder prior to fabricating the composite samples via the injection molding machine. The nanoparticles fillers were characterized by field emission scanning electron microscope (FESEM), EDX and particle size analyzer to check its morphology, composition and size distribution. Thermogravimetric analyzer (TGA) and melting flow index (MFI) were performed for the fabricated nanocomposites samples. The mechanical properties of the nanocomposite were evaluated by performing tensile test, bending test and Shore-D hardness test, while the tribological performance was investigated using a ball on desk apparatus under different applied loads and sliding times. Moreover, in order to confirm the load-carrying capability of the composite, contact stresses was measured via finite element model using ANSYS software. The results show that the incorporation of low fraction hybrid ceramic nanoparticles can contributed positively in the tribological and mechanical properties. Based on the experimental results, the maximum improvement in the tensile strength was 5.38%, and 8.15% for hardness LDPE with 0.5 Al2O3 and 0.5 SiC, while the lowest coefficient of friction was noticed under normal load of 10 N, which was approximately 12.5% for the same composition. The novel approach of incorporating low fraction hybrid ceramic nanoparticles as reinforcement for LDPE matrix is investigated, highlighting their positive contributions to the tribological and mechanical properties of the resulting nanocomposites.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47672154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-29DOI: 10.3390/inorganics11090353
Marisa James, Madelyn R. Shevlin, Thomas B. Green, M. Smart, C. McMillen, Jared A. Pienkos
Pyrazino-phenanthroline ligands are commonly used with transition metals as DNA intercalation agents. Herein, we report the characterization of two commonly utilized pyrazino-phenanthroline ligands, dipyrido[3,2-f:2′,3′-h]quinoxaline (dpq) and (benzo[i]dipyrido[3,2-a:2′,3′c]phenazine (dppn), by single-crystal X-ray diffraction. Additionally, the characterization of [Ir(ppy)2(dppn)][PF6], where Hppy = 2-phenylpyridine, by single-crystal X-ray diffraction is described. Both the dpq and dppn ligands crystallize as chloroform solvates where the chloroform molecule occupies the equivalent binding pocket of a metal in metal complexes of these ligands. These pyrazino-phenanthrolines are largely planar, with the dppn ligand displaying a slight twist. When the dppn ligand is coordinated to iridium(III), the dppn ligand on the resulting complex displays a significant degree of bending along the longitudinal direction of the ligand. This iridium (III) complex crystallizes as a CH2Cl2 and Et2O solvate and due to the volatility of these solvents these crystals are only stable for a few seconds outside of the mother liquor. The structures of the free ligands and the [Ir(ppy)2(dppn)][PF6] complex all display extensive π stacking interactions.
{"title":"Crystal Structures of DNA Intercalating Agents Dipyrido[3,2-f:2′,3′-h]quinoxaline (dpq), (Benzo[i]dipyrido[3,2-a:2′,3′c]phenazine (dppn), and [Ir(ppy)2(dppn)][PF6] (Where Hppy = 2-Phenylpyridine)","authors":"Marisa James, Madelyn R. Shevlin, Thomas B. Green, M. Smart, C. McMillen, Jared A. Pienkos","doi":"10.3390/inorganics11090353","DOIUrl":"https://doi.org/10.3390/inorganics11090353","url":null,"abstract":"Pyrazino-phenanthroline ligands are commonly used with transition metals as DNA intercalation agents. Herein, we report the characterization of two commonly utilized pyrazino-phenanthroline ligands, dipyrido[3,2-f:2′,3′-h]quinoxaline (dpq) and (benzo[i]dipyrido[3,2-a:2′,3′c]phenazine (dppn), by single-crystal X-ray diffraction. Additionally, the characterization of [Ir(ppy)2(dppn)][PF6], where Hppy = 2-phenylpyridine, by single-crystal X-ray diffraction is described. Both the dpq and dppn ligands crystallize as chloroform solvates where the chloroform molecule occupies the equivalent binding pocket of a metal in metal complexes of these ligands. These pyrazino-phenanthrolines are largely planar, with the dppn ligand displaying a slight twist. When the dppn ligand is coordinated to iridium(III), the dppn ligand on the resulting complex displays a significant degree of bending along the longitudinal direction of the ligand. This iridium (III) complex crystallizes as a CH2Cl2 and Et2O solvate and due to the volatility of these solvents these crystals are only stable for a few seconds outside of the mother liquor. The structures of the free ligands and the [Ir(ppy)2(dppn)][PF6] complex all display extensive π stacking interactions.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47121350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-27DOI: 10.3390/inorganics11090352
A. Abutaleb
Copper/sulfur co-doped titanium dioxide-carbon nanofibers (Cu,S-codoped TiO2 NPs, decorated-CNFs) catalysts were synthesized using the electrospinning process to produce composite nanofibers (NFs). These composite NFs were utilized for the hydrolysis of sodium borohydride (SBH) to generate hydrogen gas (H2), taking advantage of their catalytic properties. The experimental results demonstrated that using 100 mg of composite NFs yielded the highest catalytic activity for H2 production, generating 79 mL of H2 gas within 6 min at 25 °C and 1000 revolutions per minute (rpm) using 1 mmol of SBH. As the catalyst dosage was reduced from 100 mg to 75, 50, and 25 mg, the reaction time increased by 9, 13, and 18 min, respectively. Kinetic studies revealed that the reaction rate followed a first-order reaction, indicating a direct proportionality between the rate of reaction and the catalyst amount. Additionally, it was observed that the concentration of SBH had no influence on the reaction rate, suggesting a zero-order reaction. Increasing the reaction temperature resulted in a reduced reaction time. The activation energy was determined to be 26.16 kJ mol−1. The composite NFs maintained their superior performance over five iterations. These findings suggest that composite nanofibers have the potential to serve as a cost-effective alternative to expensive catalysts in hydrogen production.
{"title":"Synthesis of Copper/Sulfur Co-Doped TiO2-Carbon Nanofibers as Catalysts for H2 Production via NaBH4 Hydrolysis","authors":"A. Abutaleb","doi":"10.3390/inorganics11090352","DOIUrl":"https://doi.org/10.3390/inorganics11090352","url":null,"abstract":"Copper/sulfur co-doped titanium dioxide-carbon nanofibers (Cu,S-codoped TiO2 NPs, decorated-CNFs) catalysts were synthesized using the electrospinning process to produce composite nanofibers (NFs). These composite NFs were utilized for the hydrolysis of sodium borohydride (SBH) to generate hydrogen gas (H2), taking advantage of their catalytic properties. The experimental results demonstrated that using 100 mg of composite NFs yielded the highest catalytic activity for H2 production, generating 79 mL of H2 gas within 6 min at 25 °C and 1000 revolutions per minute (rpm) using 1 mmol of SBH. As the catalyst dosage was reduced from 100 mg to 75, 50, and 25 mg, the reaction time increased by 9, 13, and 18 min, respectively. Kinetic studies revealed that the reaction rate followed a first-order reaction, indicating a direct proportionality between the rate of reaction and the catalyst amount. Additionally, it was observed that the concentration of SBH had no influence on the reaction rate, suggesting a zero-order reaction. Increasing the reaction temperature resulted in a reduced reaction time. The activation energy was determined to be 26.16 kJ mol−1. The composite NFs maintained their superior performance over five iterations. These findings suggest that composite nanofibers have the potential to serve as a cost-effective alternative to expensive catalysts in hydrogen production.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48825612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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