Ni-Co/RuO2复合电极的制备及其电催化析氢性能

Preparation of Ni-Co/RuO2 Composite Electrode and Electrocatalytic Activity for Hydrogen Evolution

采用快速凝固结合去合金化的方法制备纳米多孔Ni-Co合金,利用RuO2对Ni-Co合金进行表面修饰,通过X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)对多孔材料进行物相分析和形貌表征,并通过线性扫描伏安法、多电位阶跃法、交流阻抗法和恒电流电解法测试多孔电极的电催化析氢性能。结果表明,Ni-Co/RuO2复合电极材料在50 mA·cm^-2电流密度下析氢过电位为180 mV,析氢过程由Volmer-Heyrovsky步骤控制,交换电流密度为4.42 mA·cm^-2,经10 h恒电流电解后电位仅增加20 mV,表现出良好的析氢稳定性。

Nanoporous Ni,Co and Ni-Co alloys were prepared by rapid solidification combined with de-alloying.The surface of Ni-Co alloy was modified by RuO2.The phase analysis and morphology of porous materials were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM)and transmission electron microscope(TEM).The electrocatalytic hydrogen evolution performance of the porous electrode was tested by linear sweep voltammetry,multi-potential step,alternating current impedance and potentiostatic electrolysis.The results show that the Ni-Co/RuO2 composite electrode material has a hydrogen evolution overpotential of 180 mV at a current density of 50 mA·cm-2.The hydrogen evolution process was controlled by the Volmer-Heyrovsky step,and the exchange current density was 4.42 mA·cm-2.Compared with nanoporous Ni,nanoporous Co and nanoporous Ni-Co alloy,Ni-Co/RuO2 composite electrode had the lowest apparent activation energy during hydrogen evolution.After 10 h constant current electrolysis,the potential only increased by 20 mV,showing excellent hydrogen evolution stability.