TiO2薄膜的光电催化性能及电化学阻抗谱研究

用直流磁控溅射法在钛网上制备了TiO2薄膜催化剂,采用电化学阻抗谱（EIS）对其阻抗谱特征进行了表征.同时以偶氮酸性红溶液为模型污染物,验证了此工作电极在不同条件下的光电催化活性与阻抗谱之间的关系.研究表明：光电催化实验中TiO2薄膜在同时有紫外光和外加阳极偏压的情况下,有效实现电子-空穴分离,具有最好的催化活性;最佳的外加阳极偏压值为0.3V;其EIS Nyquist图上阻抗环半径也在此时最小,最容易发生反应,与光电催化实验结果一致.

Photoelectrocatalytic Properties and Electrochemical Impedance Spectroscopy of TiO2 Thin Film Electrode by DC Reactive Magnetron Sputtering

Titanium oxide thin films were deposited by D.C.reactive magnetron sputtering from a pure 99.9% Ti disk.The results of the electrochemical impedance spectroscopy(EIS) investigation indicated that the diameters of the capacitive arcs of the TiO2 with UV and anodic bias potential were much smaller than those of dark space,thus inviting a higher photoelectrocatalytic activity.When an external bias was applied on the TiO2,the arc of EIS Nyquist plot decreased obviously than without the bias,suggesting more efficient separation of the photo-generated carriers.The degradation of azocarmine was most effective when the external potential is up to 0.3V.