TiO_2/SiO_2纳米薄膜的光催化活性和亲水性

Photocatalytic Activity and Hydrophilic Property of TiO_2/SiO_2 Composite Nanometer Thin Films

通过 sol-gel工艺在钠钙玻璃表面制备了均匀透明的 TiO_2/SiO_2复合纳米薄膜 .实验结果表明 :当 SiO_2添加量较高时 , TiO_2/SiO_2复合纳米薄膜的光催化活性明显降低 ;当 SiO_2添加量较低时 ,TiO_2/SiO_2复合薄膜的光催化活性无明显变化 .在 TiO_2薄膜中添加 SiO_2,可以抑制薄膜中 TiO_2晶粒的长大 ,同时薄膜表面的羟基含量增加 ,水在复合薄膜表面的润湿角下降 ,亲水能力增强 .当 SiO_2含量为 10％－ 20％（摩尔分数）时获得了润湿角为 0°的超亲水性薄膜 .

The uniform transparent TiO2/SiO2 composite nanometer thin films were prepared via sol-gel processing on the soda lime glass substrates, The photocatalytic activity of the as-prepared TiO2/SiO2 composite nanometer thin films obviously decreases when the amount of SiO2 addition is large, However, the photocatalytic activity has no obvious change when the amount of SiO2 addition is small (Table 2), The addition of SiO2 can suppress the grain growth of TiO2 crystal, increase the hydroxyl content of TiO2 film, decrease the contact angle for water of TiO2 films and enhance the hydrophilic property of TiO2 films. The super-hydrophilic TiO2/SiO2 composite nanometer films with the contact angle of 0 degrees were obtained by the addition of 10%-20% (mole fraction) SiO2.