Amorphous Cu-FeOOH Clusters on Oxygen-Deficient Fe-Doped BiOCl Nanoflowers for Efficient Photo-Fenton Degradation of Levofloxacin.

Efficient photo-Fenton catalysis requires the simultaneous optimization of light harvesting, photogenerated-charge utilization, and metal-mediated H2O2 activation. Herein, amorphous Cu-FeOOH clusters were assembled on oxygen-vacancy-rich Fe-doped BiOCl nanoflowers (Fe-BOCov) to construct a Cu-FeOOH/Fe-BOCov composite for efficient photo-Fenton catalysis. Oxygen-vacancy engineering and Cu-FeOOH coupling extended visible-light absorption and improved interfacial charge separation, as supported by the enhanced photocurrent response and reduced electrochemical impedance. Under AM 1.5G simulated solar irradiation, the optimized catalyst removed more than 90% of levofloxacin (LEV) within 10 min and exhibited an apparent pseudo-first-order rate constant of 0.271 min-1. Radical-quenching and electron spin resonance measurements identify •OH and •O2- as the principal reactive species, with photogenerated holes also contributing. A mechanism is proposed in which electrons generated in oxygen-vacancy BiOCl migrate to Cu-FeOOH sites, facilitate Fe(III)/Fe(II) and Cu(II)/Cu(I) cycling, and accelerate H2O2 activation. This work demonstrates a defect-and-interface strategy for coupling solar-energy utilization with bimetallic Fenton chemistry.