Publishing House SB RAS:

Publishing House SB RAS:

Address of the Publishing House SB RAS:
Morskoy pr. 2, 630090 Novosibirsk, Russia



Advanced Search

Chemistry for Sustainable Development

2021 year, number 5

Investigation of the Effect of Synthesis Conditions on the Composition and Electrochemical Properties of Nanostructured Porous Carbon Matrix/Co3O4 Composites

T. A. LARICHEV1,2, YU. A. ZAKHAROV1, N. M. FEDOROVA2, G. YU. SIMENYUK1, V. M. PUGACHEV1,2, V. G. DODONOV1,2, D. G. YAKUBIK2, T. O. TROSNYANSKAYA1
1Federal Research Centre for Coal and Coal Chemistry, Siberian Branch of the Russian Academy of Sciences, Kemerovo, Russia
2Kemerovo State University, Kemerovo, Russia
Keywords: cobalt oxide, cobalt hydroxide, cobalt azide, thermal decomposition, electric capacity, porous carbon matrix
Pages: 552-561

Abstract

The structural, morphological and electrochemical properties of nanocomposite materials of the type of a highly porous carbon matrix filled with Co3O4 are investigated. The effect of the filler preparation method (thermal decomposition of cobalt (II) hydroxide or cobalt (II) azide) in matrix pores on the characteristics of composites was considered. The composition, morphology, phase compositions of the composites, the stoichiometry of fillers, disperse and porous structures, as well as electric capacitance characteristics of the carbon matrix, precursor composites and nanostructured C/Co3O4 composites were studied using various physicochemical methods. It is established that the composites are formed through the deposition of nanoparticles of filler precursor and, during their thermal decomposition, of the target filler Co3O4 in the pores of three size groups (2-3, 7-12, and ~20 nm), and through the formation of the aggregates of filler particles on the external surface of the matrix. The nature of the effect of filler on the electric capacity of the composite depends on the method of composite formation: the capacity decreases in the composites obtained by thermal decomposition of Co(OH)2 precursor and, quite contrary, increases in the composites formed by thermal decomposition of Co(N3)2. This feature, discovered for the first time, may be related to the effect of the method of composite preparation on filler stoichiometry (the Co2+/Co3+ ratio) as determined by X-ray diffraction: the deviation of the stoichiometry from the formula-based relations between CoO and Co2O3 proceeds towards an increase in CoO fraction when the azide precursor is used, and towards an increase in the fraction of Co2O3 when the hydroxide precursor is used.

DOI: 10.15372/CSD2021333