In-situ and ex-situ characterization of surface oxide films on AB5-type metal hydride electrodes

Abstract The surface oxide films on AB 5 -type metal hydride electrodes have been investigated by means of in-situ and ex-situ techniques such as in-situ laser scanning photoelectrochemical microscopy (PEM), ex-situ scanning tunneling microscopy (STM) and in-situ confocal Raman spectroscopy. The results indicated that the growth of surface oxide films can be monitored by using in-situ photoelectrochemical methods. Both laser-scanning photoelectrochemical microscopic and confocal Raman microscopic results showed that crack sites on the electrode surface are more feasible to be oxidized than other smooth sites under electrochemical conditions. In addition, the primary surface oxide layer on fresh metal hydride electrode was found to be composite metal oxides with nickel oxide as its main component.