Enhanced Antibiotic Degradation and Antioxidant Activity Using a Novel Biosynthesized PVP-Modified Fe2O3/Fe3O4 Nanocomposite: A Dual Approach to Environmental and Human Health

This study presents the biosynthesis of a novel polyvinylpyrrolidone (PVP)-modified Fe₂O₃/Fe₃O₄ nanocomposite (NC) using an olive leaf extract. The synthesized nanocomposites exhibit dual functionality, highlighting enhanced photocatalysis and antioxidant activity, offering promising applications in environmental remediation and therapeutics. The process involves meticulous biosynthesis and PVP-mediated surface modification, confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and UV–vis analysis. Both Fe₂O₃/Fe₃O₄ NC and Fe₂O₃/Fe₃O₄@PVP NC show spherical morphologies with average sizes of 21.7 nm and 30.1 nm, and optical bandgap energies of 1.8 eV and 1.34 eV, respectively. Photocatalytic activity assessments against amoxicillin antibiotic degradation under solar irradiation highlight the superior performance of PVP-modified nanocomposites, achieving an impressive 99% removal efficiency in 50 min compared to 84% for Fe₂O₃/Fe₃O₄ NC. Kinetic investigations reveal rate constants of 0.021 min^− 1 and 0.0025 min^− 1 for PVP-modified and unmodified nanocomposites, respectively, emphasizing the enhanced degradation rates. Optimization studies showcase the mass-dependent efficiency, with PVP-modified nanocomposites achieving a remarkable 91% removal rate of amoxicillin with a 7.5 mg catalyst. The recycling performance demonstrates sustained efficacy over five consecutive cycles, with only a slight decline from 99 to 97.5%. Moreover, the nanocomposites exhibited significant antioxidant activity, with Total Antioxidant Activity (TAC) values of 5.5 and 6.86 mg GAE/mg sample for Fe₂O₃/Fe₃O₄ NC and Fe₂O₃/Fe₃O₄@PVP NC, respectively. The environmentally synthesized PVP-modified Fe₂O₃/Fe₃O₄ NC showcases promising dual functionality, making them versatile candidates for efficient pollutant degradation and antioxidant applications in environmental and therapeutic domains.