水洗处理对Au/TiO2催化剂光催化活性的影响

以Au(S2O3)3-2为金前驱体, 分别采用水洗(W)和旋蒸(E)工艺制备了Au/TiO2催化剂. 用UV-Vis漫反射光谱(DRS)、X 射线衍射(XRD)、透射电子显微镜(TEM)和原子吸收光谱(AAS)对制备的催化剂样品进行了表征, 通过光催化降解甲基橙对催化剂光催化活性进行了评价. 结果表明, 通过水洗处理, 催化剂样品表面形成了具有较好分散性的金纳米粒子(2-5 nm), 而旋蒸工艺制备的样品表面形成一层金的包覆结构. Au/TiO2催化剂的光催化活性与制备工艺密切相关. 在相似的金负载量下, 水洗法制备的样品比旋蒸法制备的样品具有更高的光催化活性.

Effect of Water Washing Treatment on the Photocatalytic Activity of Au/TiO2 Catalysts

Using Au(S2O3)3-2 as the gold precursor,Au/TiO2 photocatalysts were prepared by water washing(W)and rotary evaporation(E)processes,respectively.The samples were characterized by UV-Vis diffuse reflectance spectroscopy(DRS),X-ray diffraction(XRD),transmission electron microscopy(TEM),and atomic absorption flame emission spectroscopy(AAS).The photocatalytic activity of the samples was evaluated from the analysis of the photodegradation of methyl orange.Using the water washing treatment,well dispersed gold nanoparticles with the diameter of 2-5 nm were formed on the surface of TiO2,whereas only the gold coating was formed for rotary evaporation processes.The photocatalytic activity of Au/TiO2 photocatalysts is related to the preparation process.With a similar gold loading,the photocatalysts prepared by water washing showed higher photocatalytic activity compared to the catalysts prepared by rotary evaporation.