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采用溶胶-凝胶法制备了不同Si/Ti比的TiO2-SiO2双组分膜.用紫外光照射亚甲基蓝的分解实验比较薄膜的光催化性能.通过XRD、FTIR、HRTEM、FE-SEM、AFM以及UV-VS-NIR分光光度计等分析手段对薄膜的结构和光学性能进行了表征.结果表明:适量SiO2的引入,显著提高了TiO2薄膜的光催化活性,Si/Ti比为0.2时薄膜的光催化活性为最佳. SiO2引入TiO2薄膜后,生成了Ti-O-Si玻璃相和无定形SiO2,这两种物相聚集在TiO2 晶界周围,有效地阻止了TiO2的晶粒长大,提高了锐钛矿相向金红石相的转变温度,使复合薄膜经过500℃热处理后,只有锐钛矿相存在,有利于薄膜的光催化活性的提高.
The TiO2-SiO2 bicomponent films with different Si / Ti ratios were prepared by sol-gel method. The photocatalytic properties of the films were compared with the decomposition of methylene blue irradiated by UV light. XRD, FTIR, HRTEM, FE- UV-VS-NIR spectrophotometer was used to characterize the structure and optical properties of the films. The results showed that the introduction of the appropriate amount of SiO2 significantly enhanced the photocatalytic activity of TiO2 films. When the Si / Ti ratio was 0.2, And the best catalytic activity.The SiO2 phase and the amorphous phase of SiO2 are formed after TiO2 is introduced into SiO2 film.The two phases gather around the grain boundary of TiO2 and effectively prevent the grain growth and the increase of TiO2 The transition temperature of anatase phase to rutile phase makes the composite film only have anatase phase after heat treatment at 500 ℃, which is in favor of improving the photocatalytic activity of the film.