In the field of hydrogen production by alkaline water electrolysis,electroplated nickel-molyb-denum alloy electrodes have attracted much attention because of their high hydrogen evolution activity and simple preparation.However,the widespread cracking and peeling off of the nickel-molybdenum plating seriously affects the performance and stability of the electrode.The aim of this study is to investigate the mechanism of cracking and peeling of nickel-molybdenum electrodes and to propose a new method to avoid the cracking of the plating layer.Through the observation of bubble precipitation,crack monitoring and electrochemical measurements in the plating layer,this paper reveals that the reason of cracking of nickel-molybdenum plating layer is the shrinkage of the plating layer and the internal stress due to the re-lease of hydrogen that enters the plating layer with the electrodeposition of the metal.A new method of nickel-molybdenum electrodeposition with low bath concentration and high current density is then pro-posed.The new electrodes did not crack and the overpotential was only 260 mV at 400 mA·cm-2 current density in 1 mol·L-1 KOH alkaline solution,which was 55 mV lower than that of the nickel-molybdenum coating electrode which are susceptible to cracking.The new method not only solves the cracking and peeling problem of nickel-molybdenum electrodeposition,but also improves its hydrogen precipitation per-formance.
nickel-molybdenum alloycracksolutionhydrogen evolution electrodealkaline water elec-trolysis
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