TiO_2多孔纳米薄膜的溶胶—凝胶法制备和光催化特性研究

Photocatalytic Properties of Porous TiO 2 Nanometer Thin Films Prepared by the Sol-Gel Method

锐钛矿型ＴｉＯ２ 多孔纳米薄膜可以从含聚乙二醇的钛醇盐溶胶前驱体中通过溶胶—凝胶法制备。涂层的形貌，如孔的大小和孔的分布可以通过聚乙二醇的加入量来控制。当聚乙二醇的加入量为０～２．０ｇ 时，孔径大小在０～４００ｎｍ 范围内变化。可见光透过光谱分析表明：随着ＴｉＯ２ 薄膜中气孔孔径增大，光的散射增强，透过率减小，该ＴｉＯ２ 镀膜玻璃对于紫外线具有吸收作用。有机磷农药敌敌畏水溶液在紫外灯照射和ＴｉＯ２ 多孔纳米薄膜的共同作用下被完全降解为无机物。光催化降解实验表明：在ＴｉＯ２ 薄膜中引入气孔增强了光催化活性，孔的大小和薄膜厚度对光解率有显著的影响。当孔径大小为５０～２００ｎｍ ，镀膜次数为１０～１５ 次时。

Porous anatase TiO 2 nanometer thin films were prepared from alkoxide solutions containing polyethylene glycol by sol-gel method. The morphology of the coatings, such as pore size and pore distribution, could be controlled by the amout of polyethylene glycol. When the amount of polyethylene glycol is within the range of 0～2.0 g, the diameters of the pores in the TiO 2 thin films are in the range of 0～400 nm. The transparency of the glass with porous TiO 2 nanometer thin films in visible spectra shows: with the increase of the diameters of the pores in the TiO 2 thin films, the scattering of light was enhanced and its transmissivity was reduced, also it does not transmit ultraviolet light. Organophosphorous insecticides, dimethyl-2,2-dichlorovinyl phosphate(DDVP),were degraded in the presence of porous TiO 2 nanometer thin films by illumination with a high pressure mercury lamp. The photocatalytic degradation experiment of organophosphorous insecticide indicated that the pores in the TiO 2 thin films enhanced its photocatalytic activity, the size of the pores and the thickness of thin films obviously affected the photodegradation rate of organophosphorous insecticide.