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

摘要:

采用脉冲电镀技术获得了高活性Ni-Mo-W析氢合金阴极。以析氢反应过电位为考察指标，确定了脉冲镀Ni-Mo-W合金的最佳电镀条件，如Na2WO4·2H2O浓度、平均电流密度和占空比等。同时，系统研究了Mo和W含量对Ni-Mo-W合金镀层成分和组成的影响规律。结果表明，在二元合金中添加W能有效提高电极的析氢反应活性 (η200=80 mV)；非晶态Ni-Mo-W合金的组织结构主要取决于Mo含量；与非晶态Ni-Mo合金镀层相比，Ni-Mo-W合金析氢阴极的电化学稳定性得到一定程度的提高。

Abstract:

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 (h200 = 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.