电沉积多孔复合Ni-P/LaNi5电极及其析氢电催化性能

采用复合电沉积制备了Ni-P/(LaNi₅+Al) 复合镀层, 然后将镀层浸泡在浓碱液中除铝, 成功得到多孔复合Ni-P/LaNi₅电极. 通过扫描电镜(SEM)、能谱分析(EDS)和X射线衍射(XRD)仪等技术表征了电极的表面形貌、组成和相结构. 运用电化学线性伏安扫描(LSV)、恒电位电解、电化学阻抗谱(EIS)等手段研究了电极在20%(w) NaOH溶液中的析氢反应(HER)电催化性和稳定性. 结果表明, 与多孔Ni-P 电极相比, 多孔复合Ni-P/LaNi₅电极具有低的析氢过电位、高的比表面积和高的稳定性能; 多孔Ni-P/LaNi₅电极的析氢反应的表观活化自由能为35.44 kJ·mol^-1, 低于多孔Ni-P 的值(50.91 kJ·mol^-1).

Electro-Deposition of the Porous Composite Ni-P/LaNi5 Electrode and Its Electro-Catalytic Performance toward Hydrogen Evolution Reaction

The composite Ni-P/(LaNi₅+Al) coating was plated by the composite electro-deposition. Then, the porous composite Ni-P/LaNi₅ coating was successfully prepared by dissolution Al with the concentrated alkali solution. The composition and structure of the coating were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDS), and X-ray diffraction (XRD). In 20% (w) NaOH solution, the electro-catalytic and stable properties for hydrogen evolution reaction (HER) of the porous composite Ni-P/LaNi₅ electrode were evaluated by electrochemical linear voltammetric scanning (LSV), constant potential electrolysis, and electrochemical impedance spectroscopy (EIS). As a result, the porous composite electrode exhibits a lower over-potential for HER, a higher specific surface area, and a better stabilization than that of the porous Ni-P electrode. The apparent activation energy for HER on the porous composite Ni-P/LaNi₅ electrodes is 35.44 kJ·mol^-1, which is lower than that of the porous Ni-P (50.91 kJ· mol^-1).