SiO_2-TiO_2自清洁防反光薄膜的制备与表征

Synthesis and Characterization of Self-cleaning and Anti-reflective SiO_2-TiO_2 Nanometric Films

采用溶胶-凝胶浸渍-提拉法,通过改变镀膜顺序和镀膜速率制备了TiO2/SiO2(ST)和SiO2/TiO2(TS)型的一系列SiO2改性TiO2双层薄膜.薄膜的形貌、光透性、光催化活性、亲水性等分别用场发射扫描电镜(FESEM)、分光光度计、光降解甲基橙等表征方法进行了分析.结果表明:SiO2膜层因其低反射指数,在ST型、TS型薄膜中均能起到防反光作用;对于TS型薄膜,其光催化活性与亲水性均随表层SiO2薄膜提拉速率的增加而降低,但ST型薄膜则相反,当表层TiO2膜提拉速率为6mm/min时,所得薄膜表现出最佳的光催化活性和亲水性,进而具备最佳的自清洁性能.

A series of bi-layer TiO2/SiO2（ST） and SiO2/TiO2（TS） films were fabricated respectively by changing the coating sequences and rates,via a Sol-Gel dip-coating method.The morphology,light transmittance,photocatalytic activitiy and hydrophilicity of the obtained products were characterized by FESEM,spectrophotometer,photo-degradation of methyl orange（MO）,etc.The experimental results show that SiO2 layer can enhance the light transmittances of ST and TS films due to its lower refractive index.As to the self-cleaning function,the photocatalytic activity and hydrophilicity of TS bi-layer film are both weakened while increasing the dip-coating speed of the overlayer SiO2 film,owing to that more TiO2 is covered by SiO2.However,it is the opposite for ST bi-layer film.When the dip-coating speed of the overlayer TiO2 film reaches 6mm/min,the obtained film exhibits the best photocatalytic activity and hydrophilicity even without UV illumination,which favors greatly the self-cleaning function of the films.