Cu/WO3-TiO2光催化剂的结构与吸光性能研究

用溶胶-凝胶法制得复合半导体WO3-TiO2,用浸渍法制得Cu/WO3-TiO2光催化剂.利用XRD、Raman、TPR、IR、TEM、XPS和UV-Vis等技术研究了Cu/WO3-TiO2的物相结构、微粒尺寸和吸光性能.结果表明含量为10wt%的WO3单分子层分散在TiO2表面,粉体平均粒径15nm.WO3的引入使TiO2吸收限发生明显蓝移,WO3负载量超过单分子层分散(＞10wt%),有晶相WO3生成,光吸收性能下降.W-O-Ti键的形成加强了半导体之间的相互作用,有利于光生载流子在半导体间的输送.负载金属Cu促进四面体配位W向八面体配位W转化.

Structure and Photo Absorption Performance of Cu/WO3-TiO2 Photocatalyst

The solid material of coupled semiconductor WO₃-TiO₂, was prepared by a sol-gel method. The photocatalyst WO₃-TiO₂ supported metallic Cu was prepared by an isovolumic impregnation method. The surface structure, particle size and photo absorption performance of the materials were characterized by XRD, Raman, TPR, IR, TEM, XPS and UV-Vis. The experiment results show that 10wt%WO₃ disperses on the surface of TiO₂ support with one monolayer of non-crystalline phase, average particle size of 1wt%Cu/10wt%WO₃-TiO₂ is about 15nm. Blue shifting of photo absorption edges is observed clearly after the addition of WO₃ on the surface of TiO₂. The lattice WO₃ forms and photo absorption performance decreases when the supporting amount of WO₃ is more than that of the monolayer phase(>10wt%). The formation of bond W-O-Ti in the solid systems promotes the transfer of generating charge carriers between WO₃ and TiO₂. Loaded metalic Cu accelerates the transformation from the tetrahedrally coordinated W species to the octahedrally coordinated W species.