Effects of UV irradiation on the intensity, structure and hydrophilicity of sol-gel TiO2 films in high-humidity

Titanium oxide thin films were prepared via sol-gel method and irradiated with a 500 W high-pressure mercury lamp in high-humidity at 321 K. The intensity of the films was measured by the scratch method. The effects of irradiation on the structure and hydrophilicity of the films were measured by IR and Raman spectra and water contact angle, respectively. The results indicated that in high-humidity UV irradiation promoted hydroxy and other organic groups to break off and Ti-0-Ti bond to form, which increased the intensity, crystallization and absorption in visible region. Under UV irradiation the hydrophilicity of newly prepared films decreased firstly, then increased. Moreover, the hydrophilicity of TiO2 films is isotropic. This method can be applied in the preparation of highly intensive, crudely crystalline and hydrophilic TiO2 films. on the temperature-nonresistance materials at low temperature.