Enhanced photocatalytic performance of carbon quantum dots/Bi OBr composite and mechanism investigation

摘要

Novel carbon quantum dots(CQDs)/Bi OBr composite photocatalysts have been constructed through a facile hydrothermal synthesis in the presence of ionic liquid 1-hexadecyl-3-methylimidazolium bromide([C16 mim]Br). Series of characterizations have been performed to confirm the uniform distribution of CQDs in Bi OBr nanosheets and the synergistic effect for photocatalytic degradation organic pollutants between CQDs and Bi OBr. The results show that 3.1 wt% CQDs/Bi OBr photocatalyst possesses the best photocatalytic activity for the degradation of colorless antibiotic tetracycline(TC), endocrine disrupter bisphenol A(BPA) and dye rhodamine B(Rh B), under visible light irradiation, which exhibited the highest photocatalytic performance. The enhanced photocatalytic performance for CQDs/Bi OBr composites could be attributed to the wider optical absorption range and fast separation of photogenerated charge carriers after the introduction of CQDs. The key roles of CQDs for the enhanced photocatalytic activity of Bi OBr have been discussed. A possible mechanism of CQDs/Bi OBr on the enhancement of visible light performance was proposed.