多孔Ni-WC复合电极的制备及其在酸性溶液中的电催化析氢性能

目前,关于多孔Ni-WC电极的电催化析氢(HER)性能的报道较少。以多孔海绵镍为基体,采用复合电沉积制备多孔Ni-(WC)x复合电极。运用扫描电镜(SEM)和X射仪线衍射仪(XRD)表征电极的表面形貌和微观结构,通过阴极极化、电化学阻抗(EIS)、循环伏安、计时电流法研究多孔Ni-(WC)x电极在0.5 mol/L H2SO4溶液中的电催化析氢性能。结果表明:与多孔基体Ni电极相比,多孔Ni-(WC)x电极具有较低的析氢过电位、较低的电化学反应阻抗、较小的表观活化能以及较大的交换电流密度;随着镀液中WC浓度的升高,所制备的多孔Ni-(WC)x电极的电催化析氢活性增强,其中Ni-(WC)40电极的表观交换电流密度是多孔Ni基体电极的966.7倍,其表观活化能为5.95 kJ/mol,并具有较好的耐蚀性和析氢稳定性。

Synthesis of Porous Ni-WC Composite Electrode and Its Characterization for Electrocatalytic Hydrogen Evolution Reaction in Acidic Solution

There are few reports about the electrocatalytic hydrogen evolution( HER) performance of porous Ni-WC electrodes. Porous Ni-( WC)xcomposite electrode was fabricated by the means of composite electrodeposition on porous Ni foam substrate. The surface morphology and microstructure of the electrode were characterized by scanning electron microscopy( SEM) and X-ray diffractometer( XRD). The electrocatalytic properties of porous Ni-( WC)xfor HER in 0.5 mol/L H2 SO4 solution were investigated by means of cathodic polarization,electrochemical impedance spectroscopy( EIS),cyclic voltammetry( CV) and chronoamperometry. Results showed that the porous Ni-( WC)xcomposite electrode for HER exhibited a lower overpotential,a lower electrochemical impedance,a lower apparent activation energy and a higher exchange current density im comparison of the porous Ni electrode. With the increase of WC concentration in the bath,the electrocatalytic activity of the porous Ni-( WC)xelectrode for HER was enhanced. Among of them,the apparent exchange current density of porous Ni-( WC)40 composite electrode was 966.7 times of that of porous Ni electrode,and the apparent activation energy was 5.95 k J/mol,exhibiting superior corrosion resistance and stability for HER.