Ni-Cr-Mo-Cu多孔磷化物电极的制备及电催化析氢性能

Preparation and Hydrogen Evolution Performance of Porous Ni-Cr-Mo-Cu Phosphating Electrode

为了解决电解水析氢过程中所用电极材料的低效率、高成本问题,采用粉末冶金法—低温磷化法制备了一种Ni-Cr-Mo-Cu多孔磷化物电极。采用X射线衍射(XRD)、场发射扫描电镜(SEM)、X射线能谱分析(EDS)等对电极的物相、形貌结构以及元素分布等进行表征;通过开路电位、线性极化、交流阻抗等方法测试了磷化物电极材料的电催化析氢性能。结果表明,Ni-Cr-Mo-Cu多孔磷化物电极具有优异的析氢性能,调节磷化时间可在较大程度上提高其析氢催化活性。在室温条件下,磷化时间为2 h的Ni-Cr-Mo-Cu多孔磷化物电极在6 mol/L KOH的溶液中析氢性能较好,其析氢过电位仅有–0.19 V(vs RHE),交换电流密度为10 mA/cm2时对应的极化电位为–0.20 V(vs RHE);经开路电位测试18000 s后,电极材料的开路电位(η)从+0.80 V变化为+0.78 V(vs RHE),仅降低0.02 V,表明其具有良好的电催化稳定性。

In search for an efficient and low cost electrode material,porous Ni-Cr-Mo-Cu phosphating electrode was prepared by powder metallurgy and low temperature phosphating method.The phase,morphologic structure,and element distribution of the electrode were characterized by X-ray diffraction analysis(XRD),scanning electron microscope(SEM),and X-ray energy spectrum analysis(EDS).The electrocatalytic hydrogen evolution properties of phosphide electrode materials were tested by open-circuit potential(OCP),linear polarization curves(LSV)and electrochemical impedance spectrum(EIS).The results show that the porous Ni-Cr-Mo-Cu phosphating electrode exhibits excellent hydrogen evolution performance,which could be optimized by adjusting the phosphating time.At room temperature,the porous Ni-Cr-Mo-Cu phosphating electrode with a phosphating time of 2 h exhibits a good hydrogen evolution performance in a solution of 6 mol/L KOH,and its hydrogen evolution overpotential is only–0.19 V(vs RHE).When the exchange current density is 10 mA/cm2,the corresponding polarization potential is–0.20 V(vs RHE).After 18000 s of OCP test,the potential of the electrode material decreases by only 0.02 V(from+0.80 to+0.78 V(vs RHE)),which indicates that the electrode material has good chemical stability.