多孔TiO_2薄膜的表面微结构对甲基橙光催化脱色的影响

Effect of Surface Microstructure of Porous TiO_2 Thin Films on Photocatalytic Decolorization of Methyl Orange

从含聚乙二醇的钛醇盐溶胶前驱体出发 ,通过浸渍提拉法在玻璃表面制备了锐钛矿型多孔TiO2 薄膜 .随着前驱物中聚乙二醇加入量及分子量的增加 ,聚乙二醇热分解后在薄膜中产生气孔的数量增多 ,孔径增大 ,TiO2 薄膜表面的羟基含量也增加 .TiO2 薄膜中引入适当大小的微孔可明显提高薄膜的光催化活性 ;当孔径接近 40 0nm时 ,光的散射增强 ,透光率下降 ,薄膜的光催化活性降低 .

The porous TiO 2 anatase thin films deposited on glass were prepared from titanium alkoxide solution containing polyethylene glycol (PEG) by dip coating technique. The larger amount of PEG with larger relative molecular mass was added to the precursor solution, the larger size and more pores produced in the resultant thin films owing to the decomposition of PEG during heat treatment. The adsorbed hydroxyl content on such porous thin films was found to increase owing to the larger size and more pores in the thin films. However, the transmittance of the thin films decreased owing to scattering by the larger size and more pores. Photocatalytic degradation experiments showed that the methyl orange was efficiently decolorized in the presence of porous TiO 2 thin films, when exposing its aqueous solution to ultraviolet light, and the suitable surface microstructure of TiO 2 films enhanced remarkably the photocatalytic activity.