Electrochemical characterization of Raney nickel electrodes prepared by atmospheric plasma spraying for alkaline water electrolysis

A Raney Ni electrode was prepared by the simple and economical atmospheric plasma spraying method. It showed excellent performance for hydrogen evolution reaction (HER), as indicated by a Tafel slope of 54 mV/dec and overvoltage of 108 mV at 300 mA/cm2. The Ni–Al alloy coating contained a NiAl phase, which has a very slow Al leaching rate in alkaline solution. H2 heat treatment of the electrode enhanced the uniformity of Al distribution in the coating and adhesion of the coating to the substrate. However, the HER performance did not improve and the electrode was rendered more structurally vulnerable to deactivation.