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 Cu20 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.

Oxidation and photo-induced oxidation of glucose at a polyaniline film modified by copper particles

“…In both cases the data were recorded in 0.15 mol dm −3 NaOH. Both the bulk copper and the copper-polyaniline electrodes display the various well-defined characteristic copper oxide/hydroxide formation peaks [23][24][25]. In particular, the oxidation peak at −0.38 V/(Ag|AgCl) represents the conversion of Cu to Cu(I).…”

Passivity of ?-brass (Cu?Zn/67?33) and its breakdown in neutral and alkaline solutions containing halide ions

“…Thus the electrode surface is assumed to be covered with Zn(OH)z layer before the potential scan. Comparing the anodic peaks recorded at potentials > -1.00V for e-brass (in this study) with those reported previously for copper shows that: (a) peak A~ corresponds to the formation of a Cu(OH) film [29][30][31]; (b) peak (or shoulder) A2 is assumed to be due to transformation of Cu(OH) to Cu20 [29]; (c) peak A2 is related to the formation of a Cu(OH)2 or CuO layer [29,30,32]; and (d) peak A 3 (shown only in highly alkaline solutions) is attributable to the oxidation of Cu(II) species to Cu(III) species [33,34].…”

Oxygen electrosorption on copper single crystal electrodes in sodium hydroxide solution

“…In a study of the initial stages of anodic oxidation of polycrystaUine copper electrodes in alkaline solutions [1 ], we measured potential sweep voltammetry curves which show that formation of bulk Cu~O is preceded by electrosorption of oxygen species. The electrosorption occurs in two successive stages, each represented by a current peak, corresponding to a different submonolayer state with a different adsorption energy.…”