The electrochemical reaction mechanism of arsenic on gold analyzed by anodic stripping Square-wave voltammetry

The reaction mechanism of the oxidative stripping of As(0) accumulated on a polycrystalline gold electrode is studied theoretical and experimentally by Square-wave voltammetry (SWV). A mathematical model was developed specifically to describe this reaction mechanism. A reaction scheme E(ad)C is considered in this model, where As(0) corresponds to the adsorbed reduced species. The electrochemical oxidation of As(0) produces a soluble species that undergoes a chemical reaction with pseudo-first order kinetics. Although the reduction of hydrogen at the electrode surface can contribute to the deposition of As(0), significant evolution of H2 would compromise this process.