铈掺杂改性TiO_2的光催化性能

Photocatalytic Properties of TiO_2 Modified by Ce Doping

采用溶胶-凝胶法制备稀土金属铈(Ce)掺杂改性纳米TiO2光催化剂。运用X-射线衍射(XRD)、紫外-可见漫反射光谱(DRS)、程序升温氧吸附-脱附、透射电镜(TEM)等手段表征催化剂的组成、结构特征及与光催化性能的关联;以催化剂上甲基橙的紫外光催化降解反应为探针,探讨了掺杂前后TiO2光催化剂在紫外光下的活性规律。研究结果表明Ce的掺杂有利于抑制TiO2晶粒生长和晶型的转变,提高晶体的热稳定性,提高TiO2催化剂的可见光吸收能力;由于Ce具有贮存氧的能力,有助于TiO2催化剂对氧气的吸附,其吸附量随Ce掺杂量的增加而增加。

Ce doped nano TiO2 photocatalysts were prepared by sol -gel synthesis, and the photocatalytic degradation of methyl orange on the as - prepared catalysts were investigated. Technical methods including X ray diffraction （XRD） , UV -Vis diffuse reflectance spectroscopy {DRS） , Temperature programmed adsorption - desorption of oxygen, transmission electron microscopy { TEM } etc, were employed to investigate the correlation between the phtocatalytic performance and the nature of composition and structure of catalysts. It has been shown that the role of proper amount of Ce in single or co - doped catalysts played as to enhance the thermal sta- bility of catalyst for the suppression of growth or aggregation of crystal particles and transition of crystal phase from anantase to rutile, and to promote the circulation of oxygen storage/release, and concomitantly, increase the optical absorbance, extend the light response to the visible region, suppress the recombination of charge car- rier by trapping of photoinduced electrons, derive active radical species.