Fe~(3+)掺杂TiO_2/凹凸棒复合材料的光催化性能

采用酸催化的溶胶-凝胶法制备了一系列Fe3+掺杂TiO2/凹凸棒(Fe3+-TiO2/ATP)复合光催化剂材料。在可见光条件下,以亚甲基蓝(MB)溶液的光催化降解反应,评价了样品的光催化性能,研究了TiO2负载量、Fe3+掺杂量和焙烧温度对复合材料光催化性能的影响。在单因素实验的基础上,采用正交实验设计(L25(53))优化了催化剂的制备条件。光催化实验结果表明,MB在复合材料上的光催化降解反应遵循Langmuir-Hinshelwood(L-H)动力学模型。正交实验结果表明,当TiO2负载量为15%、Fe3+掺杂量为0.5%和焙烧温度为550℃时,得到的复合材料对MB的光催化降解效率最佳,测得表观反应速率常数kapp为6.09×10-3min-1,反应4 h后MB的降解率(Dt)可达75.88%,相同实验条件下与P25(1.51×10-3min-1)相比较,反应速率提高了4.03倍,降解率提高了45.05%。另外,复合材料的沉降性能优于P25,易于分离,是一类有应用前景的复合光催化剂。

Photocatalytic properties of Fe3+ doped TiO2/attapulgite composite material

A series of Fe~(3+) doped TiO_2/attapulgite composite photocatalyst ( Fe~(3+) -TiO_2/ATP) were synthe-sized by acid-catalyzed sol-gel process. Their photocatalytic activity was evaluated by degrading methylene blue ( MB) in aqueous solution under visible light irradiation. The influences of TiO_2 loading amounts, Fe~(3+) doping amounts and calcination temperature were studied. Based on the above results, the preparation condition of com-posite photocatalyst was optimized by the orthogonal experiments ( L_25 ( 5~3) ) . The results of photocatalytic experi-ments showed that the degradation of MB on the composite catalysts followed the Langmuir-Hinshelwood ( L-H) first-order reaction model. The optimal photocatalytic activity of composite particles was realized when the TiO_2 loading amounts was 15% , Fe~(3+) doping amounts was 0.5% and calcination temperature was 550 ℃, and the de-termined kinetic parameters k_(app) and degradation efficiency( D_t) were 6. 09 × 10~(-3)min ~(-1) and 75. 88% after 4 h of visible light irradiation, respectively. Comparing with P25 (1. 51 × 10~(-3)min~(-1)) , the apparent reaction rate con-stant increased about 4. 03 times and the photodegradation efficiency increased about 45. 05% . Furthermore, the Fe~(3+) -TiO_2/ATP composite photocatalyst exhibited easy separation property comparing with P25. The advantages of composite photocatalyst revealed its great practical potential in wastewater treatment.