紫外光下纳米TiO2薄膜亲水性机理的电化学研究

利用溶胶 凝胶方法在透明导电玻璃ITO (SnO2 ∶In)表面制备纳米TiO2 薄膜 ,XRD谱图表明TiO2 是锐钛矿晶型 ,AFM (Atomic Force Microscope)测得薄膜表面粒子约为 10 0nm .研究了ITO表面纳米TiO2 薄膜的光致亲水性变化 .通过循环伏安技术测定TiO2 薄膜电极在 2 5 3.7nm的紫外光照射后的电化学行为推测光致亲水性机理 .发现在紫外光照射一定时间后 ,TiO2 薄膜电极的循环伏安图在 +0 .0 35V处出现新的氧化峰 ;且随光照时间的增加 ,氧化峰的峰电流增大 ,溶液中的溶解氧对峰电流的大小有明显影响 .实验表明 ,在紫外光照下电极表面有Ti3 + 产生 ,证实了TiO2 薄膜的光致亲水性转变过程与Ti3 + 的生成导致的表面结构变化有关

Electrochemical Studies on the Hydrophilic Mechanism of TiO2 Thin Films under UV Irradiation

The nanometer films of TiO 2 were prepared by sol-gel method on ITO ( Indium-tin oxide, SnO 2:In ) substrate. The TiO 2 film was the anatase phase with a particle size of 100 nm from the measurements of X-ray diffraction and AFM(Atomic-Force-Microscope). Electrochemical characteristics of ITO/TiO 2 electrode under UV ( ultraviolet) irradiation were investigated using the method of cyclic voltammetry. A new oxidative peak was observed at 0.035 V when the TiO 2 electrode was irradiated by 253.7 nm UV light for a certain time. The peak current increased with the irradiation time. It was assumed that the new oxidative peak resulted from Ti 3+, which was formed during the UV illumination. The changes of hydrophilicity of the TiO 2 thin film on ITO under UV light were also observed. It was assumed that the changes of hydrophilicity of the films may be related with the formation of Ti 3+ on the surface when the film was irradiated by UV light.