Pub Date : 2024-07-31DOI: 10.1134/s0036023624600904
P. Yu. Gorobtsov, A. S. Mokrushin, N. P. Simonenko, E. P. Simonenko, N. T. Kuznetsov
Abstract
Crystal structure, morphology, and electrochromic properties of V2O5 film prepared using vanadyl alkoxoacetylacetonate as precursor have been studied. We have shown that the obtained vanadium pentoxide contains significant amount of V4+ cations, which is indicated by low electron work function. This results in material possessing anodic electrochromism (coloring upon oxidation) with rapid bleaching process (1 s upon the corresponding potential application). Anodic coloration is observed in the whole visible light spectrum, as well as in near IR region up to 1100 nm. The obtained data show high prospects for approach to formation of V2O5-based films using vanadyl acetylacetonate as precursor and application of these films as components of smart windows and displays, optical properties of which could be controlled by electrical current application.
{"title":"Application of Vanadyl Alkoxoacetylacetonate in Formation of V2O5 Electrochromic Films","authors":"P. Yu. Gorobtsov, A. S. Mokrushin, N. P. Simonenko, E. P. Simonenko, N. T. Kuznetsov","doi":"10.1134/s0036023624600904","DOIUrl":"https://doi.org/10.1134/s0036023624600904","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Crystal structure, morphology, and electrochromic properties of V<sub>2</sub>O<sub>5</sub> film prepared using vanadyl alkoxoacetylacetonate as precursor have been studied. We have shown that the obtained vanadium pentoxide contains significant amount of V<sup>4+</sup> cations, which is indicated by low electron work function. This results in material possessing anodic electrochromism (coloring upon oxidation) with rapid bleaching process (1 s upon the corresponding potential application). Anodic coloration is observed in the whole visible light spectrum, as well as in near IR region up to 1100 nm. The obtained data show high prospects for approach to formation of V<sub>2</sub>O<sub>5</sub>-based films using vanadyl acetylacetonate as precursor and application of these films as components of smart windows and displays, optical properties of which could be controlled by electrical current application.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"74 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-31DOI: 10.1134/s0036023624600825
E. P. Simonenko, A. F. Kolesnikov, A. V. Chaplygin, A. S. Lysenkov, I. A. Nagornov, I. V. Lukomskii, S. S. Galkin, A. S. Mokrushin, N. P. Simonenko, N. T. Kuznetsov
Abstract
The effect of a high-velocity flow of dissociated nitrogen on a sample of HfB2–30 vol % SiC ultrahigh-temperature ceramic materials modified with low amounts of reduced graphene oxide was studied to evaluate the potential of these materials in creating aerospace equipment intended for use in N2-based atmospheres. It was determined that, under the selected treatment conditions during a stepwise increase in the anode supply power of the plasma torch and, accordingly, in the acting heat flux at certain process parameters, the surface temperature of the sample sharply increases from ~1750 to 2000–2100°C. A further increase in the heat flux does not have an obvious and proportional effect on the surface temperature of the sample, which may indicate its high catalyticity with respect to surface recombination reactions of atomic nitrogen. It was shown that the surface layers of the material undergo a chemical transformation (removal of silicon-containing substances and formation of a new phase based on HfN), which is accompanied by a significant change in the microstructure (formation of dendrite-like structures), affecting the optical and catalytic characteristics of the surface.
{"title":"Transformation of the Surface of HfB2–SiC–C(graphene) Ultrahigh-Temperature Ceramics in a High-Velocity Flow of Dissociated Nitrogen","authors":"E. P. Simonenko, A. F. Kolesnikov, A. V. Chaplygin, A. S. Lysenkov, I. A. Nagornov, I. V. Lukomskii, S. S. Galkin, A. S. Mokrushin, N. P. Simonenko, N. T. Kuznetsov","doi":"10.1134/s0036023624600825","DOIUrl":"https://doi.org/10.1134/s0036023624600825","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The effect of a high-velocity flow of dissociated nitrogen on a sample of HfB<sub>2</sub>–30 vol % SiC ultrahigh-temperature ceramic materials modified with low amounts of reduced graphene oxide was studied to evaluate the potential of these materials in creating aerospace equipment intended for use in N<sub>2</sub>-based atmospheres. It was determined that, under the selected treatment conditions during a stepwise increase in the anode supply power of the plasma torch and, accordingly, in the acting heat flux at certain process parameters, the surface temperature of the sample sharply increases from ~1750 to 2000–2100°C. A further increase in the heat flux does not have an obvious and proportional effect on the surface temperature of the sample, which may indicate its high catalyticity with respect to surface recombination reactions of atomic nitrogen. It was shown that the surface layers of the material undergo a chemical transformation (removal of silicon-containing substances and formation of a new phase based on HfN), which is accompanied by a significant change in the microstructure (formation of dendrite-like structures), affecting the optical and catalytic characteristics of the surface.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"48 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-31DOI: 10.1134/s0036023624600291
G. O. Novitskii, A. A. Medvedeva, A. V. Koshkin, A. I. Vedernikov, N. A. Lobova
Abstract
The complexation process of tolane and α-cyclodextrin in water, aqueous-ethanol solution, and silicate hydrogel based on tetrakis(2-hydroxyethyl)orthosilicate was studied. The complex formation in solutions were confirmed by electron and 1H NMR spectroscopy, and the stability constant of the complex was determined using spectrofluorimetric titration (log K1 : 1 = 1.5). The preservation of the inclusion complex during the preparation of the gel was confirmed by electron spectroscopy.
{"title":"Spectral Properties of Tolane and Its Supramolecular Complexes in Solution and Silicate Hydrogel","authors":"G. O. Novitskii, A. A. Medvedeva, A. V. Koshkin, A. I. Vedernikov, N. A. Lobova","doi":"10.1134/s0036023624600291","DOIUrl":"https://doi.org/10.1134/s0036023624600291","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The complexation process of tolane and α-cyclodextrin in water, aqueous-ethanol solution, and silicate hydrogel based on tetrakis(2-hydroxyethyl)orthosilicate was studied. The complex formation in solutions were confirmed by electron and <sup>1</sup>H NMR spectroscopy, and the stability constant of the complex was determined using spectrofluorimetric titration (log <i>K</i><sub>1 : 1</sub> = 1.5). The preservation of the inclusion complex during the preparation of the gel was confirmed by electron spectroscopy.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"193 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-17DOI: 10.1134/s0036023623603380
O. Yu. Golubeva, Yu. A. Alikina, E. Yu. Brazovskaya, N. Yu. Ul’yanova
Abstract
The results of analysis and experimental studies of the possibilities of using synthetic aluminosilicates (montmorillonites, kaolinites, and zeolites) in medicine are presented. In particular, the following application fields are discussed: the field of enterosorption and hemosorption, the development of targeted drug delivery systems with prolonged and pH-controlled release of the active substance in various environments, as well as components of wound dressings. Montmorillonites, aluminosilicates of the kaolinite subgroup with different particle morphologies and zeolites of structural types Beta, Rho, and Y have been obtained under hydrothermal conditions and characterized by physicochemical methods. The results of studying the adsorption and desorption of model drugs (thiamine hydrochloride, and 5-fluorouracil) from porous aluminosilicate matrices of various chemical compositions in various media simulating body environments, adsorption of markers of endogenous intoxication (methylene blue), the ability of aluminosilicates to biodegrade in body environments, and studies of biological activity, in particular cytotoxicity and hemolytic activity of synthetic aluminosilicates, are presented. The results obtained show significant prospects for the use of synthetic aluminosilicates to obtain non-toxic, highly effective sorbents for medical use and drug carriers.
摘要 介绍了对合成铝硅酸盐（蒙脱石、高岭土和沸石）用于医药的可能性进行分析和实验研究的结果。特别讨论了以下应用领域：肠道吸附和血液吸附领域、开发可在各种环境中延长活性物质释放时间并控制 pH 值的靶向给药系统以及伤口敷料成分。我们在水热条件下获得了具有不同颗粒形态的蒙脱石、高岭石亚群的铝硅酸盐以及结构类型为 Beta、Rho 和 Y 的沸石，并通过物理化学方法对其进行了表征。研究结果包括：在各种模拟人体环境的介质中，不同化学成分的多孔铝硅酸盐基质对模型药物（盐酸硫胺素和 5-氟尿嘧啶）的吸附和解吸；对内源性中毒标记物（亚甲蓝）的吸附；铝硅酸盐在人体环境中的生物降解能力；以及对生物活性的研究，特别是合成铝硅酸盐的细胞毒性和溶血活性。研究结果表明，利用合成铝硅酸盐获得无毒、高效的医疗用吸附剂和药物载体具有广阔的前景。
{"title":"Directed Hydrothermal Synthesis of Aluminosilicates of Various Structural Types and Prospects for Their Use in Medicine","authors":"O. Yu. Golubeva, Yu. A. Alikina, E. Yu. Brazovskaya, N. Yu. Ul’yanova","doi":"10.1134/s0036023623603380","DOIUrl":"https://doi.org/10.1134/s0036023623603380","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of analysis and experimental studies of the possibilities of using synthetic aluminosilicates (montmorillonites, kaolinites, and zeolites) in medicine are presented. In particular, the following application fields are discussed: the field of enterosorption and hemosorption, the development of targeted drug delivery systems with prolonged and pH-controlled release of the active substance in various environments, as well as components of wound dressings. Montmorillonites, aluminosilicates of the kaolinite subgroup with different particle morphologies and zeolites of structural types Beta, Rho, and Y have been obtained under hydrothermal conditions and characterized by physicochemical methods. The results of studying the adsorption and desorption of model drugs (thiamine hydrochloride, and 5-fluorouracil) from porous aluminosilicate matrices of various chemical compositions in various media simulating body environments, adsorption of markers of endogenous intoxication (methylene blue), the ability of aluminosilicates to biodegrade in body environments, and studies of biological activity, in particular cytotoxicity and hemolytic activity of synthetic aluminosilicates, are presented. The results obtained show significant prospects for the use of synthetic aluminosilicates to obtain non-toxic, highly effective sorbents for medical use and drug carriers.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"20 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-17DOI: 10.1134/s0036023623603045
V. A. Vorozhtcov, V. L. Stolyarova, S. I. Lopatin, A. L. Shilov
Abstract
The vaporization of the carbide materials with the chemical compositions Ti2SiC, Ti3SiC2, Ti2AlC, Ti3AlC2, Zr2AlC, and Zr3AlC2 containing MAX phases and of oxycarbide systems based on these materials with hafnia additives was examined by Knudsen effusion mass spectrometry at temperatures up to 2200 K. Atomic aluminum was identified as the major vapor species over the Ti2AlC, Ti3AlC2, Zr2AlC, and Zr3AlC2 samples at 1500 K. The silicon-containing samples were less volatile than the aluminum-containing carbide materials; they vaporized observably at temperatures above 1900 K to form Si, Si2, SiC2, and Si2C vapor species. The addition of hafnia to the carbides under study led to the formation of oxygen-containing vapor species, particularly Al2O and SiO, and to a decrease in total vapor pressure over the systems formed. The least volatile materials were samples of the Ti2SiC–HfO2 oxycarbide system, and among the aluminum-containing oxycarbide systems, samples of the Zr2AlC–HfO2 system containing up to 10 mol % hafnia and samples of the Ti2AlC–HfO2 system with a higher HfO2 content.
摘要 在温度高达 2200 K 的条件下，通过克努森流出质谱法研究了化学成分为 Ti2SiC、Ti3SiC2、Ti2AlC、Ti3AlC2、Zr2AlC 和 Zr3AlC2 且含有 MAX 相的碳化物材料以及以这些材料为基础并添加了哈夫纳添加剂的碳氧体系的气化情况。在 1500 K 的温度下，Ti2AlC、Ti3AlC2、Zr2AlC 和 Zr3AlC2 样品的主要蒸气种类是原子铝。含硅样品的挥发性低于含铝碳化物材料；它们在 1900 K 以上的温度下明显蒸发，形成 Si、Si2、SiC2 和 Si2C 蒸气种类。在所研究的碳化物中加入哈夫纳，会形成含氧的气态物质，尤其是 Al2O 和 SiO，并降低所形成体系的总气压。挥发性最小的材料是 Ti2SiC-HfO2 氧碳化物体系的样品，而在含铝氧碳化物体系中，则是含高达 10 mol % 哈夫纳的 Zr2AlC-HfO2 体系的样品和 HfO2 含量较高的 Ti2AlC-HfO2 体系的样品。
{"title":"High-Temperature Mass Spectrometric Study of the Vaporization of Oxycarbide MAX Phase Ceramics","authors":"V. A. Vorozhtcov, V. L. Stolyarova, S. I. Lopatin, A. L. Shilov","doi":"10.1134/s0036023623603045","DOIUrl":"https://doi.org/10.1134/s0036023623603045","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The vaporization of the carbide materials with the chemical compositions Ti<sub>2</sub>SiC, Ti<sub>3</sub>SiC<sub>2</sub>, Ti<sub>2</sub>AlC, Ti<sub>3</sub>AlC<sub>2</sub>, Zr<sub>2</sub>AlC, and Zr<sub>3</sub>AlC<sub>2</sub> containing MAX phases and of oxycarbide systems based on these materials with hafnia additives was examined by Knudsen effusion mass spectrometry at temperatures up to 2200 K. Atomic aluminum was identified as the major vapor species over the Ti<sub>2</sub>AlC, Ti<sub>3</sub>AlC<sub>2</sub>, Zr<sub>2</sub>AlC, and Zr<sub>3</sub>AlC<sub>2</sub> samples at 1500 K. The silicon-containing samples were less volatile than the aluminum-containing carbide materials; they vaporized observably at temperatures above 1900 K to form Si, Si<sub>2</sub>, SiC<sub>2</sub>, and Si<sub>2</sub>C vapor species. The addition of hafnia to the carbides under study led to the formation of oxygen-containing vapor species, particularly Al<sub>2</sub>O and SiO, and to a decrease in total vapor pressure over the systems formed. The least volatile materials were samples of the Ti<sub>2</sub>SiC–HfO<sub>2</sub> oxycarbide system, and among the aluminum-containing oxycarbide systems, samples of the Zr<sub>2</sub>AlC–HfO<sub>2</sub> system containing up to 10 mol % hafnia and samples of the Ti<sub>2</sub>AlC–HfO<sub>2</sub> system with a higher HfO<sub>2</sub> content.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"24 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-17DOI: 10.1134/s0036023623603379
A. A. Malygin, A. A. Malkov, E. A. Sosnov
Abstract
The current state of research carried out by Valentin Borisovich Aleskovskii’s leading scientific school “Chemistry of Highly Organized Substances” is studied, including both new fundamental and applied results on the molecular layering synthesis of innovative solid-phase materials, and the most promising areas of their implementation in industry, as well as achievements in the equipment design for the molecular layering process.
{"title":"Aleskovskii’s Leading Scientific School “Chemistry of Highly Organized Substances:” from Fundamental Research to Widespread Practical Implementation","authors":"A. A. Malygin, A. A. Malkov, E. A. Sosnov","doi":"10.1134/s0036023623603379","DOIUrl":"https://doi.org/10.1134/s0036023623603379","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The current state of research carried out by Valentin Borisovich Aleskovskii’s leading scientific school “Chemistry of Highly Organized Substances” is studied, including both new fundamental and applied results on the molecular layering synthesis of innovative solid-phase materials, and the most promising areas of their implementation in industry, as well as achievements in the equipment design for the molecular layering process.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"65 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-17DOI: 10.1134/s0036023623603227
S. A. Kukushkin, A. V. Osipov
Abstract
This study provides a detailed microscopic description of the chemical transformation of a silicon crystal into a silicon carbide crystal via reaction with carbon monoxide gas at the Si(111) surface. This was done using density functional theory in the spin-polarized PBE approximation. All intermediate (adsorption) states and the single transition state were identified using the NEB method. It was shown that the transition state is an Si–O–C triangle with bond lengths of 1.94, 1.24, and 2.29 Å. Additionally, the energy profile of this chemical reaction was calculated. The presence of dangling bonds was found to generate both electric and magnetic fields during the reaction. According to the results, the relaxation of elastic energy provides efficient ordering of the growing crystals by weakening the bonds of the certain atoms. That is why the (111) surface is the optimal for silicon carbide growth by this method for semiconductor applications.
{"title":"Elastic Energy Relaxation in the Chemical Reaction of CO with Single-Crystalline Silicon during Coordinated Substitution of Atoms","authors":"S. A. Kukushkin, A. V. Osipov","doi":"10.1134/s0036023623603227","DOIUrl":"https://doi.org/10.1134/s0036023623603227","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This study provides a detailed microscopic description of the chemical transformation of a silicon crystal into a silicon carbide crystal via reaction with carbon monoxide gas at the Si(111) surface. This was done using density functional theory in the spin-polarized PBE approximation. All intermediate (adsorption) states and the single transition state were identified using the NEB method. It was shown that the transition state is an Si–O–C triangle with bond lengths of 1.94, 1.24, and 2.29 Å. Additionally, the energy profile of this chemical reaction was calculated. The presence of dangling bonds was found to generate both electric and magnetic fields during the reaction. According to the results, the relaxation of elastic energy provides efficient ordering of the growing crystals by weakening the bonds of the certain atoms. That is why the (111) surface is the optimal for silicon carbide growth by this method for semiconductor applications.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"14 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-17DOI: 10.1134/s0036023623603173
M. V. Kalinina, I. G. Polyakova, S. V. Myakin, T. V. Khamova, L. N. Efimova, I. Yu. Kruchinina
Abstract
Xerogels and finely dispersed СeO2–Nd2O3 and Gd2O3–La2O3–SrO–Ni(Co)2O3–δ mesoporous powders are synthesized by cocrystallization of the corresponding nitrate solutions with ultrasonic treatment, and used to prepare nanoceramic materials with a fluorite-like and orthorhombic perovskite crystal structures, respectively, with CSRs of ca. 55–90 nm (1300°C). The physicochemical characterization of the prepared ceramic materials revealed an open porosity of 7–11% for СeO2–Nd2O3 ceramics and 17–42% for Gd2O3–La2O3–SrO–Ni(Co)2O3–δ ceramics. Cerium oxide-based materials possess a predominantly ionic electrical conductivity with σ700°С = 0.31 × 10–2 S/cm (the ion transference number ti = 0.71–0.89 in the temperature range 300–700°C) due to the formation of mobile oxygen vacancies upon heterovalent substitution of Nd3+ for Се4+. Solid solutions based on gadolinium nickelate and gadolinium cobaltite feature a mixed electronic–ionic conductivity (σ700°С = 0.59 × 10–1 S/cm) with the electron and ion transference numbers te = 0.92–0.99 and ti = 0.08–0.01. The prepared ceramic materials are shown to be promising as solid oxide electrolytes and electrodes for medium-temperature fuel cells.
{"title":"Synthesis and Physicochemical Characterization of Solid Oxide Electrolyte and Electrode Materials for Medium-Temperature Fuel Cells","authors":"M. V. Kalinina, I. G. Polyakova, S. V. Myakin, T. V. Khamova, L. N. Efimova, I. Yu. Kruchinina","doi":"10.1134/s0036023623603173","DOIUrl":"https://doi.org/10.1134/s0036023623603173","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Xerogels and finely dispersed СeO<sub>2</sub>–Nd<sub>2</sub>O<sub>3</sub> and Gd<sub>2</sub>O<sub>3</sub>–La<sub>2</sub>O<sub>3</sub>–SrO–Ni(Co)<sub>2</sub>O<sub>3–δ</sub> mesoporous powders are synthesized by cocrystallization of the corresponding nitrate solutions with ultrasonic treatment, and used to prepare nanoceramic materials with a fluorite-like and orthorhombic perovskite crystal structures, respectively, with CSRs of ca. 55–90 nm (1300°C). The physicochemical characterization of the prepared ceramic materials revealed an open porosity of 7–11% for СeO<sub>2</sub>–Nd<sub>2</sub>O<sub>3</sub> ceramics and 17–42% for Gd<sub>2</sub>O<sub>3</sub>–La<sub>2</sub>O<sub>3</sub>–SrO–Ni(Co)<sub>2</sub>O<sub>3–δ</sub> ceramics. Cerium oxide-based materials possess a predominantly ionic electrical conductivity with σ<sub>700°С</sub> = 0.31 × 10<sup>–2</sup> S/cm (the ion transference number <i>t</i><sub>i</sub> = 0.71–0.89 in the temperature range 300–700°C) due to the formation of mobile oxygen vacancies upon heterovalent substitution of Nd<sup>3+</sup> for Се<sup>4+</sup>. Solid solutions based on gadolinium nickelate and gadolinium cobaltite feature a mixed electronic–ionic conductivity (σ<sub>700°С</sub> = 0.59 × 10<sup>–1</sup> S/cm) with the electron and ion transference numbers <i>t</i><sub>e</sub> = 0.92–0.99 and <i>t</i><sub>i</sub> = 0.08–0.01. The prepared ceramic materials are shown to be promising as solid oxide electrolytes and electrodes for medium-temperature fuel cells.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"32 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-17DOI: 10.1134/s0036023623602957
V. A. Vorozhtcov, V. I. Almjashev, V. L. Stolyarova
Abstract
The goal of this work was to study phase equilibria in the La2O3–SrO–ZrO2 system, which is a promising base for high-temperature ceramics and materials with unique optical, electrochemical, and catalytic properties. Thermodynamic modeling of phase equilibria in this system was carried out using the NUCLEA database and GEMINI2 (Gibbs Energy Minimizer) software. One polythermal and thirteen isothermal sections of the La2O3–SrO–ZrO2 phase diagram were calculated in the temperature range 600–3023 K. The obtained data on La2O3–SrO–ZrO2 phase equilibria were discussed with reference to information available on the corresponding binary systems. The modeled phase relations in the ternary system under study correlate completely with the phases existing in the corresponding binary systems. The temperature evolution of the phase relations and boundaries of single-phase, two-phase, and three-phase areas in the system were considered. Four ternary eutectic points were identified at 2039, 2105, 2120, and 2351 K.
{"title":"Modeling of Phase Equilibria in the La2O3–SrO–ZrO2 System Using the NUCLEA Database","authors":"V. A. Vorozhtcov, V. I. Almjashev, V. L. Stolyarova","doi":"10.1134/s0036023623602957","DOIUrl":"https://doi.org/10.1134/s0036023623602957","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The goal of this work was to study phase equilibria in the La<sub>2</sub>O<sub>3</sub>–SrO–ZrO<sub>2</sub> system, which is a promising base for high-temperature ceramics and materials with unique optical, electrochemical, and catalytic properties. Thermodynamic modeling of phase equilibria in this system was carried out using the NUCLEA database and GEMINI2 (Gibbs Energy Minimizer) software. One polythermal and thirteen isothermal sections of the La<sub>2</sub>O<sub>3</sub>–SrO–ZrO<sub>2</sub> phase diagram were calculated in the temperature range 600–3023 K. The obtained data on La<sub>2</sub>O<sub>3</sub>–SrO–ZrO<sub>2</sub> phase equilibria were discussed with reference to information available on the corresponding binary systems. The modeled phase relations in the ternary system under study correlate completely with the phases existing in the corresponding binary systems. The temperature evolution of the phase relations and boundaries of single-phase, two-phase, and three-phase areas in the system were considered. Four ternary eutectic points were identified at 2039, 2105, 2120, and 2351 K.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"27 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-17DOI: 10.1134/s0036023623603185
A. P. Voznyakovskii, A. A. Vozniakovskii, S. V. Kidalov
Abstract
This review is concerned with the production of 2D graphene nanostructures (few-layer graphene; FLG) by our developed method for carbonization of biopolymers implemented in a self-propagating high-temperature synthesis (SHS) process. Here, we analyze and summarize the experimental and some theoretical results, which served us to design a phenomenological model for the SHS synthesis of 2D graphene structures. The main focus is on the results obtained over the last decade. The prospects for ongoing research into the carbonization of biopolymers are discussed. Particular attention is paid to those areas of research that are expected to be of most interest for the use of few-layer graphene in the near future.
{"title":"Few-Layer Graphene Produced by the Self-Propagating High-Temperature Process from Biopolymers: Synthesis, Properties, and Application (a Review)","authors":"A. P. Voznyakovskii, A. A. Vozniakovskii, S. V. Kidalov","doi":"10.1134/s0036023623603185","DOIUrl":"https://doi.org/10.1134/s0036023623603185","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This review is concerned with the production of 2D graphene nanostructures (few-layer graphene; FLG) by our developed method for carbonization of biopolymers implemented in a self-propagating high-temperature synthesis (SHS) process. Here, we analyze and summarize the experimental and some theoretical results, which served us to design a phenomenological model for the SHS synthesis of 2D graphene structures. The main focus is on the results obtained over the last decade. The prospects for ongoing research into the carbonization of biopolymers are discussed. Particular attention is paid to those areas of research that are expected to be of most interest for the use of few-layer graphene in the near future.</p>","PeriodicalId":762,"journal":{"name":"Russian Journal of Inorganic Chemistry","volume":"49 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号