ELECTROLYTIC HYDROGEN EVOLUTION ON CO-ALLOY THIN-FILMS PREPARED BY ELECTROCHEMICAL AND AUTOCATALYTIC DEPOSITION TECHNIQUES

Various thin films of Co-based alloys deposited by chemical and electr ochemical methods have been tested as cathodes for hydrogen evolution reaction (HER) and anodes for oxygen evolution reaction (OER) in alkal ine solutions. The results obtained with the SCP (Secondary Current Pu lse) method, studying the electrochemical transients, are compared wit h amperostatic measurements. Surface coverage with the electrocatalyti c films can be followed through SCP parameter values. A general frame is proposed for the interpretation of the electrokinetic behaviour on the base of the Normality-Inertia parameter. Co20Pt20 and Co20Pd80 ele ctrodeposited thin films show interesting electrocatalytic properties towards H-2 and O-2 evolution, respectively.