Initial stages of anodic oxidation of polycrystalline copper electrodes in alkaline solution

Abstract

The first stages of the anodic oxidation of polycrystalline copper electrodes in NaOH solutions were studied by potential sweep voltammetry and ellipsometry. Formation of bulk Cu2O was found to be preceded by electrosorption of oxygen species, that occurs in two successive stages, each represented by a current peak, corresponding to a different submonolayer state with a different adsorption energy. This surface oxide was formed via random electrodeposition. The width of the first current peak indicates the presence of lateral attractive interactions in the chemisorbed layer. The surface layer did not show any ageing effect.