Photocatalytic properties of Fe3+ doped TiO2/attapulgite composite material
Fe3+掺杂TiO2/凹凸棒复合材料的光催化性能

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.