三维有序结构In掺杂TiO_2薄膜的可见光催化活性

采用自组装生长聚苯乙烯胶体模板和溶胶-凝胶法,制备出三维(3D)有序结构In掺杂TiO2(IO-TiO2-In)薄膜可见光催化剂.光催化实验证明,IO-TiO2-In薄膜降解甲醛的可见光活性是TiO2和三维有序结构TiO2(IOTiO2)薄膜的5倍.利用X射线电子衍射(XRD)谱、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)和紫外-可见(UV-Vis)漫反射吸收光谱确定了催化剂的晶相结构、表面微结构和能带结构.结果表明,IO-TiO2-In薄膜具有锐钛矿型三维有序结构,与TiO2相比,增加了比表面积,提高光的利用率;掺入的In离子在薄膜表面形成In2O3和O-In-Clx(x=1,2)物种,既增强可见光的吸收,又有效地促进了光生载流子的分离,提高了光生载流子在固/气界面参加光催化反应的利用率,使催化剂的可见光催化活性显著提高.

Visible Light Photocatalytic Activity of an In-Doped TiO2 Thin Film with a Three-Dimensional Ordered Structure

An In-doped TiO₂ thin film with a three-dimensional (3D) ordered structure (IO-TiO₂-In) was prepared by the self-assembly template method of polystyrene colloidal crystal growth and sol-gel method. The visible light photocatalytic activity of the IO-TiO₂-In thin film for the degradation of formaldehyde is five times that of TiO₂ and undoped IO-TiO₂. The crystal structure, surface microstructure, and energy band structure of the catalyst were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy. The IO-TiO₂-In thin film is an ordered anatase structure, which increases the specific surface area and photo efficiency, compared with those of pure TiO₂. Doped In ions form In₂O₃ and O-In-Cl_x (x=1, 2) species on the surface of the thin film. This increases the absorption of visible light, and promotes the separation of photogenerated charge carriers. It improves the efficiency of photogenerated charge carriers in the photocatalytic reaction at the solid/gas interface, and significantly increases the visible light photocatalytic activity.