TiN基IrO_2-Ta_2O_5涂层析氢电极的催化性能

Electrocatalytic Properties of TiN-Based IrO_2-Ta_2O_5 Coating Electrodes for Hydrogen Evolution Reaction

采用热分解法制备了以离子镀TiN膜为基体的IrO2-Ta2O5涂层电极,通过循环极化曲线并结合扫描电镜、X射线能谱和X射线衍射研究了涂层的析氢电催化性能.结果表明,涂层呈多孔多裂纹的结构,焙烧温度对涂层的表面形貌和电催化活性影响很大.420℃下焙烧的涂层具有最优的电催化活性.涂层电极的析氢反应电极电位为-0·26V(vsSCE),低析氢过电位下的Tafel斜率为-0·04V,而在高析氢过电位下,电极表面吸附的大量氢原子改变了氧化物电极的结构,从而抑制了氧的阴极还原反应.

The IrO2-Ta2O5 coating electrodes were prepared by thermal decomposition and supported on TiN films synthesized by multi-arc ion plating. The eleetroeatalytie properties of coating cathodes for hydrogen evolution reaction （HER） were investigated by cyclic polarization combined with scanning electron microscope, energy dispersive X-ray spectroscopy, and X ray diffraction. The results showed that there existed TiN substrates on the electrodes and the electrode calcined at 420 ℃ exhibited the best electrocatalytic activity for HER. Electrode potential for hydrogen evolution on coating electrodes was - 0.26 V （ vs SCE）. The Tafel slope was - 0.04 V in the low overpotential region of HER. The structure of oxide electrodes was changed by a multitude of hydrogen atoms adsorbed on the electrode surface in the high overpotential region of HER, which restrained the cathodic reduction reaction of oxygen. These results suggest primarily that it is feasible using TiN as support for the IrO2-Ta2O5 coating cathode.