Oxidation of Thiosulfate to Sulfate at Glassy Carbon Electrodes

Abstract

Thiosulfate can be quantitatively oxidized to sulfate without production of elemental sulfur (S0) by a two‐step anodic process at glassy carbon electrodes in 1.0 M buffer (pH 5). The first step, at 1.0 V vs.SCE, converts to tetrathionate . The second step, at 1.6 V vs. SCE, converts to . Addition of bromide (Br−) to solutions expedites the desired conversion, presumably because of homogeneous oxidations by bromine generated by anodic oxidation of Br−.