TiO_2光催化甲基橙电化学阻抗法表征的研究

Investigation on the TiO_2 thin film photocatalytic property characterized in methyl orange solution by electrochemical impedance method

采用溶胶-凝胶法在Al2O3薄膜表面上制备了纳米TiO2光催化薄膜(TiO2/Al2O3),将此薄膜用于光催化降解甲基橙,采用电化学阻抗法分析了TiO2薄膜光电极在甲基橙溶液中暗态、光照、不同光强以及改变阳极偏压时的交流阻抗图谱。结果表明,电化学阻抗谱能够较好的反应光催化、光电催化降解甲基橙的实验过程;并且发现施加阳极偏压可提高薄膜的催化性能,发现0.4 V左右最佳。

Nano-TiO2 thin film（TiO2/Al2O3） was prepared on the surface of porous Al2O3 film by the sol-gel method.Then the TiO2/Al2O3 film was employed to investigate the proccess of the degradation of methyl orange.And the electrochemical impedance spectra of the TiO2 film was analyzed under conditions of having no lights,light with various wavelengths and changed anodic bias.The results indicated that the electrochemical impedance spectra can reflect the experiment process of the photocatalysis and the electrolphotocatalysis preferably.Besides addition of anode voltage could improve the catalystic performance of the film,and the effect quite well over 0.4 V.