Home – Home – Jornals – Chemistry for Sustainable Development 2021 number 6

The work is devoted to the synthesis and study of porous carbon materials: thermally expanded graphite (TEG), carbon nanofibres, and activated carbon. The possibility of using them in electrochemical current sources, in particular, in supercapacitors, was investigated. The physicochemical properties of the obtained samples were studied by low-temperature nitrogen adsorption, cyclic voltammetry, and electron microscopy. The modification of carbon materials was carried out in three ways, and the effect of the modification on the values of specific capacitance and surface area was studied. It is revealed that the samples are characterized by the well developed porous structure: for initial materials, the maximum surface area was 759 m²/g, while for the composites obtained as a result of modification, it was 187 m²/g. It was shown that the highest specific capacitance was typical for the materials possessing micro- and mesoporous structure, with an average pore size of 3-5 nm. Modification of the surface of carbon materials with nickel led to a decrease in the specific surface area, an increase in the average pore diameter, and also, in some cases, to an increase in the specific capacitance. Among the materials with deposited nickel particles, the maximum specific capacity (116 F/g) was exhibited by a composite of 20 mass % NiО/80 mass % TEG. Treatment with nitric acid and mechanical activation led to an increase in the fraction of micropores in the samples and to an increase in the specific capacitance. The data obtained prove that the studied carbon materials are highly promising for electrochemical applications.