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8 results on '"Belmesov, A. A."'

1. Synthesis and Properties of Rubidium Salts of Phosphotungstic Acid

Author

Andrey A. Belmesov, Alexander A. Glukhov, Maxim V. Tsvetkov, Lyubov V. Shmygleva, Timofey A. Shikhov, Aleksey O. Lembikov, Anton A. Belov, Nikita P. Ivanov, and Oleg O. Shichalin

Subjects
rubidium salts, phosphotungstic acid, heteropoly compounds, synthesis, morphology, ionic conductivity, Technology, Science
Abstract

The work is devoted to the study of the influence of synthesis conditions on the properties of water-insoluble rubidium salts of phosphotungstic acid (PTA). Such heteropoly compounds have a wide range of applications, including in the field of electrocatalysts and solid electrolytes for various electrochemical devices. The acid salts of PTA with high activity of acid sites on the particle surface are of particular interest. It is known that the properties of water-insoluble PTA salts strongly depend on synthesis conditions, such as the ratio of reagents, temperature, concentrations, and other parameters. The work examines the influence of the ratio and concentration of reagents on the sizes of crystallites and agglomerates, specific surface area (SSA), porosity, water content, and ionic conductivity of the synthesized PTA salts. The SSA value of the obtained samples varied in the range of 84–123 m2 g−1, and the ionic conductivity was 13–90 mS cm−1 at room temperature and 75% RH. An increase in the acid concentration and the degree of proton substitution led to an increase in SSA, accompanied by an increase in particle sizes without changing the size of crystallites. The results of the work may be useful for the development of new materials based on the obtained salts in many fields, including hydrogen energy.

Published
2023
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6. Electrical conductivity of lanthanum oxide based composites containing carbon nanofibers

Author

P. V. Fursikov, Boris P. Tarasov, A. A. Belmesov, A. A. Volodin, M. N. Abdusalyamova, Igor I. Khodos, and Yu. M. Shul'ga

Subjects
Materials science, Carbon nanofiber, General Chemical Engineering, Composite number, Metals and Alloys, chemistry.chemical_element, Conductivity, Ceramic matrix composite, Inorganic Chemistry, chemistry.chemical_compound, Lanthanum oxide, chemistry, Electrical resistivity and conductivity, Nanofiber, Materials Chemistry, Lanthanum, Composite material
Abstract

We have measured the electrical conductivity of lanthanum oxide based composite materials containing different concentrations of carbon nanofibers as additives. The conductivity has been shown to increase sharply (by two orders of magnitude) at carbon nanofiber contents from 2 to 3 wt % owing to the formation of a three-dimensional network of nanofibers in the bulk of the composite. Particular attention has been paid to the morphology of the particles of the constituent components of the composites and to the chemical and phase compositions of the matrix material.

Published
2014

7. Electro-conductive composites based on titania and carbon nanotubes

Author

A. A. Volodin, P. V. Fursikov, A. A. Belmesov, A. D. Zolotarenko, V. B. Murzin, and Boris P. Tarasov

Subjects
Materials science, General Chemical Engineering, Metals and Alloys, Carbon nanotube, Electrochemistry, Electrocatalyst, Conductive composites, law.invention, Inorganic Chemistry, Chemical engineering, Electrical resistivity and conductivity, law, Materials Chemistry, Ultrasonic sensor, Mass fraction, Carbon nanomaterials
Abstract

Carbon-ceramic composites have been prepared by mechanical ball-milling and ultrasonic treatment of mixtures of titania with carbon nanomaterials, and the optimal preparation conditions have been determined. The dependence of electrical conductivity of the composites on the mass fraction of carbon nanomaterials (1–5 mass. %) has been ascertained, and it has been found that a carbon nanotubes mass fraction of 3% gives rise to a sharp increase in the electrical conductivity up to 2.2 × 10−3 S/cm. It has been shown that the carbon-ceramic composites are promising electrocatalyst supports for electrochemical applications.

Published
2013

8. Electro-Conductive Composites Based on Metal Oxides and Carbon Nanostructures

Author

Volodin, A.A., Tarasov, B.P., Belmesov, A.A., Gerasimova, E.V., Zolotarenko, A.D., and Shchur, D.V.

Subjects
Carbon nanotubes, Electrical conductivity, Carbon-ceramic nanocomposites, Catalytic activity
Abstract

Optimal conditions were found for the formation of carbon-oxide composites by the treatment of mixtures of oxides of aluminum or titanium with carbon nanotubes and nanofibers in a planetary ball mill. The dependences of the electrical conductivity of composites on the content of carbon nanomaterials (1-5% by mass) were determined. It is shown that the addition of 3%(wt) of CNT to the oxides leads to a sharp increase in the electrical conductivity: from 5.0×10-8 to 2.8×10-4 S/cm for Al2O3 and from 5.0×10-6 to 2.2×10-2 S/cm for TiO2. It was shown that the carbon-oxide composites are promising carriers of the catalysts of electrode processes in electrochemical devices. It was revealed that Pt/TiO2 - CNT catalyst containing 5% (mass) of carbon nanotubes has the best catalytic activity in oxygen reduction, in an electrode-modeling cathode of a fuel cell. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35124

Published
2012

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