Facile Synthesis of Magnetic Visible-Light Activated Photocatalyst Znfe2o4/Bivo4/G-C3n4 for Decomposition of Antibiotic Lomefloxacin : Photocatalytic Mechanism, Degradation Pathway, and Toxicity Assessment

Magnetic ZnFe2O4/BiVO4/g-C3N4 (ZBC) composites were prepared via a facile hydrothermal and calcination method for the degradation of a representative antibiotics lomefloxacin (LFX) under visible light irradiation. The optimal photocatalyst ZBC-10 with a ZnFe2O4:BiVO4:g-C3N4 mass ratio of 1:8:10 performed 96.1% removal of LFX after 105 min of illumination. The excellent performance is ascribed to the effective construction of heterojunctions and its capacity to form a double Z-scheme charge transmission pathway among the hosts in ZBC-10. The composite enhanced the separation and migration of photoexcited charge carriers and the effective generation of multiple active radicals. Three degradation pathways for LFX were identified based on an integrated HPLC-Q-TOF-MS analysis and density functional theory computation of the Fukui indices. Ecotoxicological evaluation confirmed the reduced toxicity of transformation intermediates over photocatalysis. Convenient magnetic recovery, high performance, and high recyclability made ZBC-10 a promising visible-light-activated photocatalyst for practical implementation in eliminating antibiotics from wastewater