ELECTROCHEMISTRY OF NICKEL-OXIDE ELECTRODE .6. SURFACE OXIDATION OF NICKEL ANODES IN ALKALINE SOLUTION

Applications of a potentiostatic anodic step charging method (described in the following paper) have been made to the study of the involvement of surface oxide species in the oxygenevolution reaction at nickel electrodes in alkaline solution. The potential range covered included a region where faradaic oxygen evolution can occur. Under these conditions, a method based on principles described in the following paper must be adopted, since currents of both a faradaic (for the over-all reaction) and a pseudo-faradaic (for the surface charging process) origin pass in a common range of potentials. The potential-sweep method under these conditions yields results that are difficult to interpret. Comparison of the result obtained with those from the latter method and from the galvanostatic reduction method is made over appropriate ranges of potential. The formation of various oxide species at the electrode surface is indicated by studies on the stoichiometry of the oxide, as determined by chemical methods. The surface oxide formation or reduction charges are found to be logarithmic well potential up to and well beyond apparent monolayer coverage. © 1969.