采用溶胶一凝胶一浸渍法制备了锐钛矿型SO42-/TiO2纳米光催化剂,并通过X射线衍射(XRD)、BET比表面积测量和透射电镜(TEM)对其进行了表征。以对苯二甲酸作为探针分子,结合化学荧光技术研究了光催化剂表面羟基自由基的生成;在紫外和可见光的照射下,以甲基橙为光催化反应的模型化合物,研究了锐钛矿型SO42-/TiO2纳米光催化剂的光催化活性。结果表明:SO4^2-负载使锐钛矿TiO2的比表面积增加,吸附量增加,光催化活性提高;SO42-/TiO2纳米光催化剂的羟基自由基的生成速率越大,催化剂的催化活性越高;浸渍液H2SO4的浓度对SO42-/TiO2纳米光催化剂的吸附量、羟基自由基的生成速率和催化活性有一定的影响,H2SO4的最佳浓度为0.2mol/L。
Anatase SO42--/TiO2 nano-photocatalysts were prepared by sol-gel-impregnation method and charac- terized by means of XRD,BET and TEM. The hydroxyl radicals produced in the supernatant of the irradiated catalyst suspension containing terephthalic acid were also investigated by measuring the fluorescence derived by the reaction with terephthalic acid. The photocatalytic activities of as-prepared anatase SO42-/TiO2 nano-photocatalysts were eva luated by photocatalytic conversion of methyl orange as model compound under UV and visible light irradiation. As a result, when SO42- was loaded on anatase TiO2 catalyst, its BET surface area increased, adsorption quantity in creased, and photocatalytic activity was enhanced. The higher the formation rate of hydroxyl radical on the SO42 / TiO2 catalyst, the higher the photocatalytic activity. H2 SO4 concentration affected the photocatalytic activity, adsorption quantity, and formation rate of hydroxyl radical. The optimal concentration of H2 SO4 is 0. 2 mol/L.