紫外光照下纳米TiO_2电极的电化学行为

Electrochemical Behavior of ITO /TiO_2 Electrode under UV Illumination

通过电沉积方法制备了纳米TiO2薄膜电极,应用循环伏安和交流阻抗技术研究了TiO2电极在253.7nm的紫外光照射下的电化学行为.结果表明,TiO2薄膜电极的循环伏安图在+0.15V处出现新的氧化峰,交流阻抗谱的半圆明显减小,电极的开路电位在有光和无光的情况下呈现规律变化.实验证实在紫外光照射下电极表面有新物种Ti3+生成,但光生Ti3+不稳定.

The electrode of nanothin film of TiO 2 was prepared by electrodeposition method on ITO surface.Electrochemical beh avior of ITO /Ti O 2 electrode under UV illumination was investigated using the methods of cycli c voltammetry and AC impedance spectroscopy.A new oxidative peak a ppeared at 0.15V when the TiO 2 electrode was illuminated under 253.7nm light.It belongs to a new spec ie s of photo induced Ti 3+ .The complex-plane impedance plots for I TO /TiO 2 electrode in a solution containing N a 2 SO 4 at open circuit potential exhibit semicircular shapes.The ap parent resista nce decreased when th e electrode was irradiated by UV light.It is confirmed th at a new species was pr oduced when the electrode of nanofil m TiO 2 under 253.7nm light irra-diation.The open-circuit potentia l of an e lectrodeposition TiO 2 film electrode varied regularly with light on and o ff.This result shows that the TiO 2 electrode has the typical characteristics of n-type semiconductors.It als o indicates that photo-induced Ti 3+ is not stable in the solution.