Electrochemical studies of copper, nickel and a Cu55/Ni45 alloy in aqueous sodium acetate

This paper discusses the electrochemical behavior of copper, nickel and a copper/nickel alloy in aerated aqueous 0.10 and 1.0 mol L-1 sodium acetate. The data obtained from different electrochemical techniques were analyzed to determine the influence of Ni and Cu on the electrochemical processes of the alloy electrode. The shapes of the potentiodynamic I(E) curves of the alloy were found to be quite similar to those of the Ni voltamograms. Although the anodic current densities of Ni and the alloy increased with greater concentrations of acetate, the opposite effect occurred in Cu. The impedance measurements taken at the open circuit potential revealed that the polarization resistance (R P) of the electrodes decreased in the following order: Ni > Alloy > Cu. With increasing concentrations of acetate, the R P of the alloy and the Cu increased while that of the Ni electrode decreased.