Fe3+掺杂TiO2/凹凸棒复合光催化剂的制备和光催化活性

用酸催化溶胶-凝胶法制备了Fe³⁺掺杂TiO₂/凹凸棒（Fe³⁺-TiO₂/ATP）复合光催化剂，对其结构、微观形貌、光吸收性能和可见光下的光催化性能进行了表征。XRD和TEM测试结果表明，Fe³⁺-TiO₂/ATP具有较好的热稳定性，经450 ℃热处理后的ATP晶体结构基本保持不变，锐钛矿TiO2均匀的分布在ATP表面，TiO2颗粒之间无团聚，且平均粒径小于纯TiO₂。UV-Vis-DRS测试结果表明，Fe³⁺的掺杂可明显增强复合光催化剂对可见光的吸收，光响应范围拓展到了整个紫外-可见光区。在可见光下，Fe³⁺-TiO₂/ATP复合光催化剂对亚甲基蓝具有很好的催化降解活性。Fe³⁺-TiO₂/ATP的反应速率常数分别为TiO₂/ATP、P25和纯TiO2的1.37、4.83和6.51倍。复合光催化剂的沉降性能优于纯TiO2和P25，易于分离。

Preparation and Photocatalytic Activity of Fe3+ Doped TiO2/Attapulgite Composite Photocatalyst

Fe³⁺ doped TiO₂/attapulgite composite photocatalyst(Fe³⁺-TiO₂/ATP) was synthesized by acid-catalyzed sol-gel method, and the structure, morphology, light absorption properties and photocatalytic activity under visible light irradiation were investigated. XRD and TEM analyses reveal that the crystalline structure of ATP in the composite photocatalyst was found thermally stable after being treated at 450 ℃. TiO₂ nanoparticles with anatase form were uniformly dispersed on the surface of ATP without aggregation and the average crystallitesize of TiO₂ nanoparticles in the composite photocatalyst was smaller than that of the neat TiO₂. UV-Vis-DRS shows that the doping of Fe³⁺ could extend the light response of the composite photocatalyst from UV to visible light region. The Fe³⁺-TiO₂/ATP composite photocatalyst exhibited higher photocatalytic activity for the degradation of methyl blue(MB) and the determined apparent reaction rate constant were about 1.37 times that of TiO₂/ATP, 4.83 times that of P25 and 6.51 times that of neat TiO₂, respectively. Furthermore, the composite photocatalyst showed easy separation property compared with neat TiO₂ and P25.