Ni/LaNi_5多孔复合电极的制备及其析氢电催化性能

Preparation and Electrocatalytic Performance for Hydrogen Evolution Reaction of the Ni/LaNi_5 Porous Composite Electrode

先电沉积Ni-Zn合金镀层,然后用浓碱将镀层中的锌脱溶,得到多孔镍,最后采用复合电沉积将LaNi5镶嵌到多孔镍表面,制备成Ni/LaNi5多孔复合电极。采用稳态极化曲线和交流阻抗谱对电极的电催化析氢性能进行了评价,并运用恒电位间歇电解和长时间电解,开路电位等研究了电极的电析氢稳定性。结果表明:Ni/LaNi5多孔复合电极的析氢表观交换电流密度分别是镍和多孔镍的172倍和26倍;多孔复合电极中的LaNi5具有稳定电极的作用,该电极比多孔镍具有更优异的抗断电性能。

At first, the Ni-Zn coating was electroplated, then, the coating was immersed in concentrated alkali solution to remove zinc and the porous nickel was obtained. Finally, the Ni/LaNi5 porous composite electrode was prepared on this porous nickel surface by means of the composite electro-deposition. The electro-catalytic properties for hydrogen evolution reaction of the electrode were evaluated by electrochemical steady-state polarization curve and electrochemical impendence spectroscopy （EIS）. And the stability of the electrode was studied by open circuit potential and constant potential electrolysis technology for long time and discontinuity electrolysis. Results show that the apparent exchange current density of the porous composite electrode is 172 and 26 times as much as that of the nickel electrode and the porous nickel electrode, respectively. Because LaNi5 possesses the effect of electrode protection, the stability of the porous composite electrode is better than that of the porous nickel.