不同波长紫外光照下纳米TiO2薄膜的光致亲水性与循环伏安行为

通过溶胶-凝胶方法分别在ITO和玻璃表面制备了纳米TiO_2薄膜，研究了纳米 TiO_2薄膜在254及365nm的紫外光照射下的循环伏安行为和光致超亲水性。在紫外 光的照射下，TiO_2薄膜电极可表现出两个光电化学过程，纳米TiO_2薄膜的光致超 亲水性转变及两个光电化学过程的速率均取决于紫外光的波长，原因在于纳米 TiO_2薄膜对两种波长的光的吸收率和光子的能量不同。提出了光电化学过程的机 理，认为紫外光照射下纳米TiO_2薄膜的超亲水性变化与产生Ti~(3+)的过程引起的 表面微观结构变化存在的一定的内在联系。

Photo-induced Hydrophilicity and Cyclic Voltammetric Behavior of TiO_2 Thin Film under Ultraviolet Illumination with Different Wavelengths

TiO 2 thin films were prepared by a sol gel method on ITO and glass substrates. The hydrophilicity change under two wavelength UV light was investigated by the determination of the contact angle of water. Cyclic voltammetric behavior of ITO/TiO 2 electrode under ultraviolet (UV) illumination with different wavelength was measured in the solution of Na 2SO 4. Two photoelectrochemical processes for TiO 2 thin film electrode under UV illumination can be observed. The conversion rates of hydrophilicity of the TiO 2 thin film and the two photoelectrochemical processes were determined by the wavelength of the UV light. The main reason is that ultraviolet light with short wavelength has high energy and absorbance. A mechanism was proposed on the base of these two photoelectrochemical processes. It is assumed that the change of hydrophilicity of the films was related with the changes of surface structure when the film was irradiated by UV light.