摘要
用溶胶 凝胶法制备了复合半导体MoO3 TiO2 ,并用等体积浸渍法制备了Cu/MoO3 TiO2 光催化剂 .利用X射线衍射、激光拉曼光谱、程序升温还原、红外光谱、透射电镜和紫外 可见漫反射光谱等技术研究了所得光催化剂的物相结构、微粒尺寸和吸光性能 .结果表明 ,MoO3 含量为 10 %时呈单分子层分散在TiO2 上 ,催化剂的平均粒径为 10nm .MoO3 的引入使TiO2的吸收限发生明显的蓝移 ,MoO3 负载量超过 10 %时 ,有体相MoO3 生成 ,其光吸收性能下降 .Mo 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传输 .负载金属Cu可促进四面体配位Mo向八面体配位Mo转化 .
The composite semiconductor MoO 3-TiO 2 was prepared by sol-gel method and a new type Cu/MoO 3-TiO 2 photocatalyst was prepared by an isovolumetric impregnation method. The surface structure, particle size and photoabsorption performance of the catalyst were characterized by X-ray diffraction (XRD), laser Raman spectroscopy (LRS), temperature-programmed reduction (TPR), infrared spectroscopy (IR), transmission electron microscopy (TEM) and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The results showed that the supporting of MoO 3 on bulk TiO 2 restrained the increase of TiO 2 crystal diameters and its change from anatase to rutile. The average particle size of the catalyst was 10～20 nm and MoO 3 dispersed on the TiO 2 support surface with one monolayer of non-crystalline phase. The dispersion threshold value of MoO 3 on TiO 2 support was 10%. The blue shift of photoabsorption edges was observed clearly after the addition of MoO 3 on the TiO 2 surface. The crystallite MoO 3 appeared and the photoabsorption performance decreased when the MoO 3 amount was more than the dispersion threshold. The formation of Mo-O-Ti bonds in the catalyst promoted the transfer of photo-generated current carriers between MoO 3 and TiO 2. Loading of metal Cu on the composite semiconductor MoO 3-TiO 2 improved the transformation from the tetrahedrally coordinated Mo species to the octahedrally coordinated Mo species.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2004年第11期862-868,共7页
基金
国家重大基础研究前期研究专项 ( 2 0 0 1CCA0 3 60 0 )资助
关键词
氧化钼
氧化钛
复合半导体
铜
负载型催化剂
光吸收性能
molybdena, titania, composite semiconductor, copper, supported catalyst, photoabsorption performance
