ZIF-derived CoFe2O4/Fe2O3 combined with g-C3N4 as high-efficient photocatalysts for enhanced degradation of levofloxacin in the presence of peroxymonosulfate

The construction of heterostructures is an effective way of improving the photo-induced charge carrier migration rate of photocatalysts. In this study, a novel ZIF-derived CoFe2O4/Fe2O3@g-C3N4 (ZIF-CFO/FO@CN) composite was prepared using a feasible coprecipitation and high-temperature calcination approach. The separation of photo-induced charge carriers was effectively promoted due to the formation of Z-scheme heterostructure between g-C3N4 (CN) and ZIF-derived CoFe2O4/Fe2O3 (ZIF-CFO/FO). Meanwhile, combining ZIF-CFO/FO with CN could significantly boost the light response capability and reduce the bandgap of pure CN. Then, the obtained hybrid catalysts were used as an efficient mediator to activate peroxymonosulfate (PMS) for degrading levofloxacin (LVFX) under visible light illumination. The 15% ZIF-CFO/FO@CN composite exhibited the best photocatalytic performance for LVFX degradation, and LVFX of 95.1% was degraded within 40 min. Some factors influencing the degradation process in the 15% ZIF-CFO/FO@CN/Vis/PMS system are also discussed. Moreover, the mechanism of the LVFX degradation in this system was analyzed in detail based on the various characterization, LVFX degradation efficiency evaluation, radical species identification, and radical trapping results. The possible LVFX pathway was speculated based on the HPLC-MS measurement. This investigation explored the performance of photocatalysts coupled with PMS for degrading antibiotics from sewage and provided an efficient method for contaminated water treatment. (c) 2022 Published by Elsevier B.V.