Electric Arc Synthesis of Composite Ni–C, NiO–C Nanomaterials: Structure and Electrochemical Properties

Electric arc sputtering of a composite nickel–carbon electrode leads to the plasma‐chemical synthesis of nickel nanoparticles packed in a carbon matrix. Nickel nanoparticles in the synthesized material are surely separated from each other by carbon structures, which prevent their agglomeration, coagulation. The carbon component of the material has both high graphitizable and less graphitizable structures. An increase in the calcination temperature of the synthesized nanomaterial in an oxygen‐containing medium leads to gradual burnout of the less graphitizable carbon structure and oxidation of nickel nanoparticles. Partial burnout of the less graphitizable carbon structure leads to an improvement in electrical conductivity and an increase in the specific capacitance of the material as the electrode material of supercapacitors. Complete burnout of the less graphizable carbon structure leads to the agglomeration of nickel oxide nanoparticles and to the decrease in the specific surface of the material, which leads to a decrease in the specific capacitance of the material as the electrode material of supercapacitors. Plasma‐chemical synthesis allows to produce Ni–NiO–C nanomaterial. Ni nanoparticles are surrounded by a carbon matrix. Burning out of amorphous and low graphitizable carbon structures improves the material's electrical conductivity and electrochemical properties as supercapacitor electrodes. Higher temperature calcination leads to deterioration of the electrochemical properties due to carbon burning out and nanoparticle agglomeration.