采用水热法,以多壁碳纳米管(MWCNTs)、溴化钾和硝酸铋为原料,制备得到MWCNTs/BiOBr复合光催化剂。以刚果红有机染料为目标污染物,研究了该光催化剂在氙灯下的可见光催化活性。考察了光催化剂用量、刚果红初始质量浓度、阴离子种类等因素对光催化刚果红脱色效果的影响及其稳定性。研究表明,碳纳米管的引入使该复合材料的光催化性能和吸附性能都明显优于单一的BiOBr。催化剂用量为1.5 g/L,刚果红初始质量浓度为15 mg/L,光催化处理120 min的条件下,脱色效率高达99%。反应体系中起主要作用的活性物质为空穴(h+)和羟基自由基(·OH)。经过4次重复循环使用,刚果红的脱色率仍能达到92%以上。
The composite photocatalyst carbon nanotube/BiOBr(MWCNTs/BiOBr) was prepared by hydrothermal method using multi-walled carbon nanotubes(MWCNTs), KBr and Bi(NO_3)_3·5H_2O as raw materials.The photocatalytic activity of the photocatalyst under xenon lamp was studied using congo red as the target pollutant. The effects of photocatalyst dosage, congo red initial concentration, anion species on the decolorization of congo red were investigated and the stability of photocatalyst was also verified. The results showed that the introduction of carbon nanotubes could make the photocatalytic activity and adsorption performance of the MWCNTs/BiOBr composite significantly better than BiOBr. The decolorization was as high as 99%when catalyst dosage was 1.5 g/L, the initial concentration of congo red was 15 mg/L, and the photocatalytic time was 120 min. The main active species in the reaction system were hole(h+) and hydroxide radical(·OH).The decolorization of congo red could still reach more than 92% after 4 repeated cycle use.