Effective norfloxacin elimination via photo-Fenton process over the MIL-101(Fe)-NH2 immobilized on α-Al2O3 sheet

MIL-101(Fe)-NH2@Al2O3 (MA) catalysts were successfully synthesized by reactive seeding (RS) method on α-Al2O3 substrate, which demonstrated excellent photo-Fenton degradation performance toward fluoroquinolone antibiotics (i.e., norfloxacin, ciprofloxacin, and enrofloxacin). The structure and morphology of the obtained MA were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), atomic force microscope (AFM). The as-prepared MA could accomplish > 90% of norfloxacin degradation efficiency for 10 cycles’ photo-Fenton processes, owing to its excellent chemical and water stability. In addition, the effects of operational factors including H2O2 concentration, foreign ions, and pH on the photo-Fenton degradation of norfloxacin over MA were clarified. The ESR spectra further document that •O2−, 1O2 and •OH radicals are prominent in the decomposition process of antibiotic molecules. Finally, the plausible photo-Fenton norfloxacin degradation mechanisms were proposed and verified.