磁性BiOBr复合材料光催化降解有机染料废水

Photocatalytic degradation of organic dye solution by magnetic BiOBr composites

采用水热法合成磁性Co Fe2O4/Bi OBr复合材料,运用XRD、SEM、EDX、VSM等进行结构表征和分析,考察了催化剂用量、刚果红初始质量浓度和重复使用对复合材料光催化脱色有机刚果红染料效果的影响,评估了磁性复合材料的回收性能,并探讨了光催化刚果红的脱色机理。磁性Co Fe2O4/Bi OBr复合材料粒度均匀,大小在10~15 nm;复合材料用量为1.0 g/L,刚果红初始质量浓度为15 mg/L时,经过4 h光催化后,复合材料对刚果红的脱色效率可达93%;复合材料第4次重复使用时,对刚果红染料仍具有80%以上的脱色效果,表明磁性Co Fe2O4/Bi OBr复合材料有较好的重复使用性;自由基淬灭实验证实,磁性Co Fe2O4/Bi OBr降解刚果红的过程主要以空穴氧化机理为主。

The magnetic CoFe2O4/Bi OBr composites were synthesized by hydrothermal method. The composites were characterized by XRD, SEM, EDX, VSM. The effects of photocatalyst dosage, initial dye concentration and reuse of photocatalyst on decolorization of congo red（CR） were investigated. The recovery properties of magnetic composites were evaluated, and the mechanism of photocatalytic decolorization of congo red was also discussed. The particle size of magnetic CoFe2O4/Bi OBr composites was uniform and the size was10-15 nm. When the dosage of the composite material was 1.0 g/L and the initial concentration of congo red was 15 mg/L, the decolorization efficiency of the composite material to congo red could reach 93% after 4 h photocatalysis. When the composite was reused for fourth times, it still had more than 80% decolorization effect on congo red dye, which showed that the magnetic CoFe2O4/Bi OBr composite had good reusability. Radical quenching experiments confirmed that the main mechanism of magnetic CoFe2O4/Bi OBr degradation of congo red was hole oxidation.