TiO_2-SiO_2复合薄膜光催化活性与亲水性关系的研究

RELATIONSHIP BETWEEN PHOTOCATALYTIC ACTIVITIES AND SUPER-HYDROPHILICITY OF TiO_2-SiO_2 COMPOSITE FILMS

采用溶胶凝胶法在载玻片表面制备了均匀透明的TiO2 -SiO2 超亲水性薄膜。利用XPS ,XRD ,IR等对光催化活性和亲水性关系进行了研究。结果表明 :薄膜的亲水性与光催化活性协同作用是其保持自清洁的关键。添加SiO2 后 ,复合氧化物中表面形成Lewis酸 ,薄膜表面吸附的羟基含量增多且稳定。在与有机物竞争吸附过程中 ,水优先吸附 ,可提高薄膜的超亲水性和光催化活性 。

The TiO2-SiO2 film on the surface of glass plate with uniform transparency and super-hydrophilicity was prepared by the sol-gel method. The relationship between the photocatalytic activity and the super-hydrophilicity for the composite film was investigated by measuring the XPS, X-ray diffraction, UV-Vis spectrum and FTIR. The results show that the synergetic effect of hydrophilicity and photocatalysis can improve and maintain the self-cleaning effect. The SiO2 addition increases the acidity and form the Lewis acidity, which results in the increase of the hydroxyl content and the improvement of the stability of the hydroxyl in the composite film. The consequence is that the hydrophilicity and the photocatalytic activity can be increased during the UV irradiation and the self-cleaning effect can be enhanced.