Anodic oxidation of thiosulfate ions at a carbon-based electrode with deposited Au-particles

Abstract

In the present work, the anodic oxidation of thiosulfate ions in neutral electrolytes at a carbon-based composite electrode with deposited submicron gold particles was studied using the direct current voltammetry method. It is shown that the oxidation process is displayed in the voltammetric curves in the form of two peaks of anodic current, the magnitude of which depends on the experimental conditions. An explanation of the most probable mechanism of the oxidation reactions of S2O32– ions at an anodically polarized gold-containing electrode has been proposed. It has been shown a possibility to monitor low concentrations of thiosulfate ions (0.1-10 μM) using a current peak at potentials E>1.0 V (vs. Ag/AgCl/1M KCl). The accuracy parameters of the analytical procedure were verified, practical applications of the analytical method have been outlined.