Electrodeposition of Nickel and Cobalt Oxides onto Platinum and Graphite Electrodes for Alkaline Water Electrolysis

Smooth, compact, and bright films of nickel and cobalt oxides were prepared from 0.5 M acetate aqueous solutions and electrodeposited onto platinum and graphite electrodes. Oxygen evolution potentials in at room temperature were about 150–170 mV lower on nickel(III) oxide and cobalt(III) oxide anodes than on bare anodes. Scanning electron micrographs of deposits showed no morphological change after extensive electrolysis, and electrocatalytic activity was stable in long‐term controlled‐potential coulometric electrolysis. However, the electrocatalytic activity of showed initial decay followed by a fairly constant behavior. No visible change in the surface of the deposit was observed after extensive electrolysis.