Interfacial engineering-mediated S-Scheme heterojunction with dual-ion cycling for enhanced photo-Fenton degradation of levofloxacin using a magnetically recyclable MnFe2O4@MIL-101(Fe) catalyst.

The uniform pore size distribution and inherent particle inseparability of iron-based metal-organic frameworks (Fe-MOFs) have been shown to significantly hinder their light-harvesting capabilities and charge carrier separation efficiency. These intrinsic limitations compromise catalyst recyclability and reaction kinetics in practical scenarios, thereby impeding their applicability in the degradation of antibiotic pollutants such as levofloxacin (LEV) in aquatic environments. Here, we report an S-type heterojunction photocatalyst, MnFe2O4@MIL-101(Fe), prepared via hydrothermal coupling of magnetic MnFe2O4 nanoparticles with MIL-101(Fe). The synergistic effect of Fe3+/Fe2+ and Mn3+/Mn2+ redox pairs, combined with the heterojunction interface and built-in electric field, significantly enhances visible-light-driven photo-Fenton activity. The catalyst degraded over 95% of LEV with a rate constant of 0.05056 min-1 and retained 87% activity after five cycles. LC-MS analysis revealed defluorination and demethylation pathways, while toxicity assessments confirmed lower LC50, mutagenicity, and developmental toxicity of intermediates, validating the environmental viability of the photo-Fenton process.