银纳米颗粒修饰TiO2薄膜的结构,光学及光催化性能

Structural,optical and photocatalytic properties of TiO2 films decorated with Ag nanoparticles

采用电子束沉积技术在石英玻璃、硅片基板上沉积了TiO2薄膜,利用热蒸发技术在TiO2薄膜表面沉积了不同厚度的Ag膜,研究了Ag膜厚度对TiO2薄膜结构、形貌、光学和光催化性能的影响。利用紫外-可见分光光度计(UV-VIS)、X射线衍射仪(XRD)、冷场发射电子显微镜(SEM)对沉积后的薄膜分别进行光学、结构、形貌分析。利用能谱仪测定了元素成分及含量。用光催化降解亚甲基橙(MO)的速率评价了合成的Ag-TiO2的光催化性能。结果表明:Ag纳米粒子在TiO2表面均匀分布;制备的Ag修饰多孔TiO2纳米薄膜具有优异的光催化性能。测试结果表明:在250℃下制备的TiO2薄膜为无定形结构;随着Ag膜厚度的增加,样品的光催化活性提高。当Ag膜厚度为3.7nm时,光催化活性最高;与纯TiO2相比,Ag-TiO2具有更高的光催化活性。

TiO2 films were deposited employing electron beam evaporation technique on fused silica and Si substrates and silver nanoparticles with different thicknesses were deposited on TiO2 films surface by thermal evaporation technique.The effect of Ag thickness on the structural,morphological,optical and photocatalytic properties of the nanocomposite thin films was investigated,and these properties were obtained by UV-Vis spectrophotometer,X-ray diffraction(XRD),scanning electronmicroscopy(SEM),respectively.The composition and content of elements were determined by energy dispersive spectrometer.The photocatalytic performances of the as-synthesized Ag-TiO2 were evaluated in terms of their photodegradation rate of methyl orange(MO) in an aqueous solution under light.The results show that the Ag nanoparticles are well dispersed on porous TiO2 surface.The as-prepared Ag-decorated porous TiO2 films exhibits excellent photocatalytic properties.The results indicate that the as-deposited Ag-TiO2 thin films are amorphous.It indicates that photocatalytic activity of the samples is enhanced with the thickness of Ag increased until reach to 3.7 nm.The Ag-TiO2 films show an enhanced photocatalytic activity compared with pure TiO2 films.