Electrochemical studies of the nickel electrode for the oxygen evolution reaction

The oxygen evolution reaction (OER) has been investigated on a polished pure nickel anode in 30 wt% KOH solution under the temperature range 30–70 °C. The influence of electrochemically formed Ni(II) oxide on the nickel electrode was studied and it was found that Ni(II) oxide is being transformed to Ni(III) oxide due to the change in the valence state of active sites of the electrode material. Both the anodic and cathodic peak currents were found to increase steadily with time but at a decreasing rate. With increasing temperature, a shift of the peak potential towards the positive direction and a lowering of the potential difference between the anodic and cathodic peaks indicates a shift of equilibrium potential for oxygen evolution to more negative values and a decrease in the overpotential for this reaction.