纳米ZnO电极的制备及光电催化降解苯酚的研究

On the preparation of nanometer ZnO electrode and photoelectrocatalytic degradation of phenol

采用溶胶-凝胶法制备纳米ZnO粉体,通过X射线衍射和透射电镜研究了纳米ZnO粉体的结构和形貌。XRD和TEM测试表明,所制备的ZnO粉体,具有六方晶系纤锌矿结构,晶粒平均线性粒径约为30 nm。以涂覆法制备纳米ZnO电极,考察外加电压、电极间距离和支持电解质浓度对苯酚降解率的影响。结果表明:在室温(20℃)下,外加电压2.0 V、电极间距离为0.60 cm、支持电解质Na2SO4的浓度为0.070 mol/L时,苯酚的降解率可达70%。动力学研究表明,苯酚降解反应为一级反应。

Nanometer ZnO powders were prepared by sol-gel method. Structure and surface morphology were studied by XRD and TEM. The XRD and TEM results of ZnO powders indicated that： the ZnO powders was the hexagonal wurtzite structure, the average linear particle size of crystal grain was 30 nm. The nano-ZnO electrode was prepared by coating technique. The effects of operating parameters such as the external potential, the distance between the electrode and the concentration of electrolyte on phenol degradation rate were examined. The results show that the degradation efficiency of phenol reaches 70% under the conditions of external potential 2.0 V, distance between the electrodes 0. 60 em, Na2SO4 concentration 0. 070 mol/L and 20 ℃. The kinetic study shows that degradation reaction of phenol is the first grade reaction.