电解水过程ZnO电极表面氢物种行为的表征

Behavior Characterization of Hydrogen Species on ZnO Electrode during Electrolytic Reduction of Water

ZnO表面氢物种能够显著改变ZnO的性能并参与催化化学反应,研究氢物种在ZnO表面的行为对提高ZnO的催化活性至关重要.本文利用电化学分析方法并结合扫描电镜、原位拉曼光谱和光致发光光谱研究了电解水过程中ZnO表面氢物种行为.结果表明,在较负的电势下水在ZnO电极表面还原生成氢物种并扩散进入ZnO晶格占据晶格间隙位和氧缺陷位,两种氢物种具有不同的氧化电势.利用扫描电镜、原位拉曼光谱和光致发光光谱研究了氢物种对ZnO的形貌结构和电子结构的影响.结果有助于理解ZnO表面与氢相关的催化及电催化过程.

The behavior of hydrogen production on ZnO electrode during the electrolytic reduction of water was investigated by cyclic voltammetry(CV)and cathode polarization experiments combined with in situ Raman and photoluminescence spectroscopy.CV experiments indicate that hydrogen species prefers to diffuse into the ZnO bulk at negative potentials and occupies oxygen vacancies and interstitial sites.Meanwhile,the H_(2)O reduction is self-enhanced during the electroreduction process,as evidenced by the trace crossing of the CV curves and the chronoamperometric experiment.The influence of the H species on the ZnO electrode during the electrocatalytic processes was characterized by the in situ Raman and photoluminescence spectroscopies.These results help us to understand the hydrogen-related catalytic or electrocatalytic processes on ZnO surfaces.