Electrochemical Properties of Pulse Plating Amorphous Ni-Mo-W Alloy Coating in Alkaline Medium

The amorphous Ni-Mo-W alloy coating with high HER (hydrogen evolution reaction) activity was obtained by pulse plating. In view of HER overpotential, the optimum electrodeposition conditions to prepare Ni-Mo-W coating in pulse plating process were determined, e.g. Na2WO4·2H2O concentration, average current density and duty cycle. Correspondingly, the effects of molybdenum and the tungsten contents on the compositions and the components of Ni-Mo-W coatings were investigated systematically. The results show that adding tungsten into Ni-Mo binary alloy coating could increase the HER activity effectively (η200 = 80 mV) and the amorphous microstructure of Ni-Mo-W coating mainly depends on the molybdenum content. After long-term electrolysis, compared with amorphous Ni-Mo coating, the electrochemical stability of amorphous Ni-Mo-W coating is improved to some extent due to the poor dissolution of molybdenum and tungsten.