BiOBr-TiO_2的醇热法合成及光催化活性的研究

Synthesis of BiOBr-TiO_2 by solvothermal method and research of its photocatalytic activity

采用简单的醇热法制备了BiOBr-TiO_2系列纳米复合材料,研究其对染料罗丹明B(Rh B)和无色小分子水杨酸(SA)的光催化特性。结果表明,在可见光照射下(λ≥420 nm),该系列光催化剂对有机污染物均具有良好的光催化降解性能,随材料制备体系中异丙醇钛加入量的增加,催化剂的吸附性能和光催化性能都有较大改变。其材料制备体系中钛铋摩尔比为1∶1时,制备的催化剂BiOBr-TiO_2-1.0在吸附平衡时可吸附40%的RhB,加光后10 min,即可使溶液中的Rh B完全褪色,表现出优良的吸附和光催化性能。采用光谱分析跟踪测定光催化反应过程中氧化物种的变化,表明催化过程主要涉及超氧自由基(O_2·^-)的氧化,同时空穴也直接参与底物的氧化过程。

BiOBr-TiO2 was prepared by simple one-pot alcohol thermal method. Rhodamine B（ RhB） and colorless small molecular salicylic acid（ SA） were used as target compounds to evaluate the photocatalytic activity of BiOBr-TiO2. The result showed that BiOBr-TiO2-1. 0 has the highest photocatalytic activity and fairly big adsorption capacity when the molar ratio of bismuth to titanium was 1. 0. By studying the active species generated in the photodegradation process,it was found that the catalytic oxidation process involves holes and superoxide radical（O2·-） and other oxidizing species generation.