低温制备纳米晶TiO_2薄膜及其光催化性能

LOW TEMPERATURE PREPARATION AND PHOTOCATALYTIC PROPERTIES OF NANO TiO_2 THIN FILMS

以无机盐TiOSO4、氨水、H2O2为原料,通过沉淀、胶溶、络合、回流等步骤制备了含有锐钛矿晶粒的回流溶胶(refluxedsol,RS)。以RS为前驱体在玻璃基片上用红外灯100℃干燥,在低温下制备了纳米TiO2薄膜,采用X射线衍射、热重、扫描电镜、紫外可见光吸收光谱等测试手段对TiO2薄膜进行了表征。结果表明:低温制备的TiO2薄膜呈透明状,在可见光下透光率超过80%,附着力良好,薄膜表面均匀分布着球形锐钛矿晶粒,晶粒粒径随回流时间延长而增加。以10mg/L甲基橙为降解对象,考察了TiO2薄膜的光催化性能,由100℃回流6h的RS–6溶胶制备的TiO2薄膜光催化性能最好,120min内甲基橙脱色率达到99%以上,说明采用RS前驱体制备的TiO2薄膜光催化性能良好。

Refluxed sols （RS） were synthesized using titanyl sulfate （TiOSO4）, ammonia and peroxide （H2O2） as starting materials through precipitating, peptizing, complexing and reflux. Nano anatase TiO2 thin films on glass slides were prepared from the RS precursors after drying under infrared light at low temperature. X-ray diffraction, thermogravimetry-differential thermal analysis, scanning electronic microscope and ultraviolet-visible spectrum were applied to characterize the TiO2 thin films. The results indicate that the TiO2 films prepared from RS are transparent and their maximal light transmittance exceeds 80 % under visible light, and the films have good adherence to substrates. Well-dispersed spherical anatase crystals were found on the surfaces of TiO2 films and the films are uniform and compact. The photocatalytic properties of the TiO2 films were investigated for the degradation of 10 mg/L methyl orange. TiO2 thin films prepared from RS-6, which were refluxed at 100℃ for 6h, show the best photocatalyfic activities, and the degradation rate of the methyl orange solution reached 99% after irradiation for 120 min under UV light, which proves TiO2 films prepared from RS exhibiting high photocatalytic activities.