Functional composition and electrochemical characteristics of oxidized nanosized carbon

Abstract

The functional composition and electrochemical behavior of the samples of N121 oxidized nanosized technical carbon in aqueous electrolytes are studied. For oxidation a 30% aqueous hydrogen peroxide (H₂O₂) solution and 2% H₂O₂ with the addition of singlet oxygen or ozone were used. By means of X-ray photoelectron spectroscopy data and the analysis of the near edge X-ray absorption fine structure the features of the chemical structure of the samples are found. The oxygen concentration did not exceed 5 at.% in the samples. The analysis of cyclic voltammograms reveals that at low scan rates the specific capacitance of the material is determined by the functional composition of the surface. The sample oxidized by 30% H₂O₂ solution and containing the largest number of–OH and–COOH groups demonstrated the highest capacitance in 6M KOH and in 1М H₂SO₄ it was the sample with the highest concentration of C=O groups formed during the oxidation with singlet oxygen. The stability of carbon electrodes is studied in supercapacitor models.