Synthèse et caractérisation de matériaux à base de nickel raney dopé aux éléments à effet électro-catalytique dans la production de l'hydrogène par électrolyse

Abstract

The aim of this work is the synthesis of highly active and low-cost electrode materials to be used as cathodes in alkaline water electrolysis. The study was focused on the deposition of nickel-zinc (NiZn) alloys from a Watts-type nickel plating bath and the treatment of the resulting films in an appropriate solution before being inoculated with a thin layer of platinum. It is found that the Ni-Zn alloy synthesized from a bath with Zn/Ni molar ratio=10, was composed mainly of a highly corrosion resistant γ- Ni-Zn phase. The chemical leaching of Zn from these alloys leaded to the formation of Ni-Raney type electrodes with high specific surface area. Subsequent Pt-electrochemical doping of Ni-Raney films enhanced both of the anti-corrosion and electro-catalytic properties towards HER in alkaline water electrolysis. On the other hand, the study of the first instants of electro-formation of the deposits showed that the nucleation of Ni-Zn deposits followed an instantaneous (or progressive) nucleation model, depending on the experimental conditions, particularly the Zn/Ni molar ratio in the bath and the applied cathodic overvoltage.