Highly efficient degradation of levofloxacin by magnetic Fe3O4@TiO2 photocatalyst: mechanistic insights and toxicity evaluation.

This study investigates the photocatalytic degradation of levofloxacin (LVF) using TiO2 and Fe3O4@TiO2 composite synthesized via the sol-gel method. TiO2 nanoparticles calcined at 350 °C exhibited optimal performance, then coupled with commercial Fe3O4 to obtain the Fe3O4@TiO2 composite. Characterization included XRD, SEM, EDS, FTIR, BET, and UV-Vis spectroscopy. Under UVA irradiation, optimal LVF removal (96.26%) was achieved at pH 5.45, with 300 mg/L catalyst and 10 mg/L LVF after 150 min. ●O2- was identified as the dominant species, followed by h+, 1O2, and ●OH. Enhanced degradation efficiency (98.98%) was obtained in the Fe3O4@TiO2/PDS/UVA system compared to the PMS and H2O2 systems. The kinetic analysis confirmed pseudo-first-order. The catalyst exhibited good stability and efficiency over five cycles. Degradation pathways, ecotoxicity, and antibacterial effects of intermediates were analyzed by HPLC-MS/MS, ECOSAR, and disk diffusion assays. These findings demonstrate Fe3O4@TiO2 as an efficient and reusable photocatalyst for LVF removal in wastewater treatment.