Novel CNT/PbBiO2Br hybrid materials with enhanced broad spectrum photocatalytic activity toward ciprofloxacin (CIP) degradation

In this work, novel multiwalled carbon nanotube (CNT)/PbBiO2Br composite photocatalysts have been prepared using reactable ionic liquid (IL) assisted solvothermal method. On the surface of PbBiO2Br ultrathin nanosheets, the CNT are uniform distribution. The obtained CNT/PbBiO2Br materials exhibit markedly enhanced photo-catalytic performance for the photodegradation efficiency of antibiotic agent CIP under ultraviolet, visible and above 580 nm light irradiation. The introduction of CNT plays vital role in promoting the photocatalytic activity of CNT/PbBiO2Br composite catalysts. The CNT promote light absorbance, reduce the impedance and act as photoinduced electron separation center as well as pollutant degrading activity center. The electron spin resonance and active species trap experiments reveal that the O-2(center dot-) and holes are the main active species during the photocatalytic process. Compared with pure PbBiO2Br, the molecular oxygen activation ability of CNT/PbBiO2Br composite photocatalyst is evident promotion. A possible photocatalytic mechanism of CNT/PbBiO2Br materials has been proposed based on a series of experimental analysis. The strategy for the preparation of high-performance photocatalysts can be extended to design and tune other advanced broad spectrum photocatalytic materials.