镍基TiO_(2)复合电极的制备及电催化析氢性能

Preparation of Ni-based TiO_(2) composite electrode and its electrocatalytic activity for hydrogen evolution reaction

在含有TiO_(2)颗粒的氨基磺酸体系镀镍液中通过电沉积制备了Ni/TiO_(2)复合镀层。采用扫描电子显微镜(SEM)、红外吸收光谱(FTIR)和X射线衍射(XRD)对镀层进行表征的结果显示,TiO_(2)颗粒成功地沉积在镍镀层中,并改变了镍镀层的表面微观形貌和相结构。通过极化曲线、塔菲尔曲线、电化学阻抗谱(EIS)、计时电位曲线等电化学测试考察了不同TiO_(2)质量浓度下所得Ni/TiO_(2)复合镀层的析氢活性和稳定性。与Ni镀层相比,Ni/TiO_(2)复合镀层显示出更高的析氢催化活性。TiO_(2)表面存在的羟基有利于析氢反应中氢吸附原子的形成,提高了析氢反应速率。在10 mA/cm^(2)的阴极电流密度下,以6 g/L TiO_(2)制备的复合镀层表现出较低的析氢过电位(310 mV),具有最高的析氢活性。

Ni/TiO_(2) composite coatings were prepared by electrodeposition in a sulfamate-based bath containing TiO_(2) particles.The characterization of the electrodeposited coatings by scanning electron microscopy(SEM),infrared absorption spectroscopy(FTIR),and X-ray diffraction(XRD)showed that TiO_(2) particles were successfully deposited in the nickel coating,changing the surface micromorphology and phase structure of the nickel coating.The catalytic activity and stability of the composite coatings prepared with different mass concentrations of TiO_(2) for hydrogen evolution reaction(HER)were examined by steady-state polarization,Tafel plot measurement,electrochemical impedance spectroscopy(EIS),and chronopotentiometry.The Ni/TiO_(2) composite coatings showed higher catalytic activity for HER than the pure Ni coating.The presence of hydroxyl groups on TiO_(2) surface facilitates the formation of adsorbed hydrogen atoms in HER,accelerating the rate of HER.The Ni-based composite coating prepared with 6 g/L of TiO_(2) in the bath exhibited a lowest overpotential(310 mV)for HER at a cathodic current density of 10 mA/cm^(2),showing the highest catalytic activity for HER.