Hierarchically Porous Gd3+-Doped CeO2 Nanostructures for the Remarkable Enhancement of Optical and Magnetic Properties

Rare earth ion-doped CeO2 has attracted more and more attention because of its special electrical, optical, magnetic, or catalytic properties. In this paper, a facile electrochemical deposition route was reported for the direct growth of the porous Gd-doped CeO2. The formation process of Gd-doped CeO2 composites was investigated. The obtained deposits were characterized by SEM, EDS, XRD, and XPS. The porous Gd3+- doped CeO2 (10 at% Gd) displays a typical type I adsorption isotherm and yields a large specific surface area of 135 m2/g. As Gd3+ ions were doped into CeO2 lattice, the absorption spectrum of Gd3+-doped CeO2 nanocrystals exhibited a red shift compared with porous CeO2 nanocrystals and bulk CeO2, and the luminescence of Gd3+-doped CeO2 deposits was remarkably enhanced due to the presence of more oxygen vacancies. In addition, the strong magnetic properties of Gd-doped CeO2 (10 at% Gd) were observed, which may be caused by Gd3+ ions or more oxygen defects in deposits. In addition, the catalytic activity of porous Gd-doped CeO2 toward CO oxidation was studied

Terahertz Radiation-Resistant Nanoceramics

Изобретение относится к радиационно стойким оптическим терагерцовым материалам, конкретно к терагерцовой нанокерамике на основе галогенидов серебра и одновалентного таллия, предназначенной для ядерной физики, фотоники, лазерной и ИК волоконной оптики, с выходом в оптическое изделие до 90 %. Нанокерамика выполнена на основе бромида серебра и дополнительно содержит йодид серебра и йодид одновалентного таллия при следующем соотношении ингредиентов, мас.%: бромид серебра 75,0-80,0; йодид серебра 15,0-5,0, йодид одновалентного таллия 10,0-15,0. Основу новой терагерцовой радиационно стойкой нанокерамики составляет бромид серебра кубической модификации, который является матрицей. В решетке AgBr равномерно распределены наночастицы TlI и AgI орторомбической модификации, которые обеспечивают, во-первых, высокую дефектность кристаллической решетки, что значительно уплотняет структуру, а во-вторых, придают устойчивость нанокерамики к радиационному излучению. Нанокерамика прозрачна в терагерцовой области и широком спектральном диапазоне от 0,55 до 60,0 мкм. 3 пр., 1 ил.FIELD: ceramics. SUBSTANCE: invention relates to radiation-resistant optical terahertz materials, specifically, to terahertz nanoceramics based on silver and monovalent thallium halides, intended for nuclear physics, photonics, laser and IR fibre optics, with an output to an optical product up to 90%. Nanoceramics are based on silver bromide and additionally contain silver iodide and monovalent thallium iodide, with the following ratio of ingredients, wt.%: silver bromide 75.0 to 80.0; silver iodide 15.0 to 5.0, monovalent thallium iodide 10.0 to 15.0. The basis of the new terahertz radiation-resistant nanoceramics is cubic silver bromide, which is a matrix. Orthorhombic TlI and AgI nanoparticles are evenly distributed in the AgBr lattice, providing, first, high defect rate of the crystal lattice, which compacts the structure significantly, and second, imparting the nanoceramics with radiation resistance. The nanoceramics are transparent in the terahertz region and a broad spectral range from 0.55 to 60.0 mcm. EFFECT: creation of radiation-resistant terahertz nanoceramics. 1 cl, 3 ex, 1 dwg

Preparation and characterization of Me2O3-CeO2 (Me = B, Al, Ga, In) mixed oxide catalysts

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Preparation and Characterization of Me2O3-CeO2 (Me = B, Al, Ga, In) Mixed Oxide Catalysts. 2. Preparation by Sol-Gel Method

International audienceAcidic carbon nano-fiber (H-CNF) with high surface area (H-HSCNF) was prepared via the activation of CNF by KOH and then HNO3, which was highly active for the hydrolysis of DMM. Activation of phenolic resin (PR) with KOH and then HNO3 produced acidic carbon (H-HSPRC) that was even more active for the hydrolysis of DMM. The complex catalysts combining Cu–ZnO/γ-Al2O3 and H-HSPRC exhibited excellent performance for the reforming of DMM to produce H2 with a rate of H2 production as high as 7400 ml gcat-1 h-1 at 513 K

Preparation and characterization of Me2O3-CeO2 (Me = B, Al, Ga, In) mixed-oxide catalysts

The present work is focused on the synthesis and characterization of ceria-based mixed oxides. Ceria was combined with the other oxides from group III, with the intention of improving the catalytic properties I of thus obtained materials. (B2O3, Al2O3, Ga2O3, In2O3)-CeO2 mixed oxides with a wide range of Me2O3 contents have been prepared by a coprecipitation route. The obtained solid materials have been characterized in terms of their structural, textural, and surface properties, including the acid-base and red-ox features, by a variety of techniques (BET, XRD, Raman, SEM, TG, TPR-TPO). The acid-base properties were estimated by the adsorption of probe molecules (NH3 and SOA investigated by the use of two techniques: microcalorimetry and XPS. The obtained materials exhibited satisfactory homogeneity; the highest surface areas were achieved for Al2O3-CeO2 mixed oxides. Only the fluorite structure of CeO2 was observed by XRD for all prepared mixed oxides, along with the presence of oxygen vacancies, which has been proven by Raman spectroscopy. Red-ox properties were investigated for In2O3-CeO2 samples. The degree of reduction decreased with In2O3 loading. Besides, the reduction -oxidation cycle, performed up to 830 degrees C, changed the morphology and structure of the samples irreversibly, leading to crystallization of In2O3. Among all investigated materials, only boria created significant acidity, whereas the basicity has been found to be dependent on the nature and amount of group III metal

Correlation between physico-chemical characteristics and electrical capacitance of tin oxide supported on alumina catalysts

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Adsorption capacity of tin oxide supported catalysts to capture air pollutants

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Adsorption capacity of tin oxide supported catalysts to capture air pollutants

International audienc

Influence of the reactant gas on the electrical properties of alumina-supported tin dioxide catalysts

ENERGIE+GPONon

Prevalence and genetic diversity of group a rotavirus genotypes in moscow (2019–2020)

Group A rotavirus (RVA) infection is the leading cause of hospitalization of children under 5 years old, presenting with symptoms of acute gastroenteritis. The aim of our study was to explore the genetic diversity of RVA among patients admitted to Moscow Infectious Disease Clinical Hospital No. 1 with symptoms of acute gastroenteritis. A total of 653 samples were collected from May 2019 through March 2020. Out of them, 135 (20.67%) fecal samples were found to be positive for rotavirus antigen by ELISA. RT-PCR detected rotavirus RNA in 80 samples. Seven G-genotypes (G1, G2, G3, G4, G8, G9, and G12) and three P-genotypes (P[8], P[4], and P[6]) formed 9 different combinations. The most common combination was G9P[8]. However, for the first time in Moscow, the combination G3P[8] took second place. Moreover, all detected viruses of this combination belonged to Equine-like G3P[8] viruses that had never been detected in Russia before. The genotype G8P[8] and G9P[4] rotaviruses were also detected in Moscow for the first time. Among the studied rotaviruses, there were equal proportions of Wa and DS-1-like strains; previous studies showed that Wa-like strains accounted for the largest proportion of rotaviruses in Russia. © 2021 by the authors. Licensee MDPI, Basel, Switzerland