Constructing a magnetic type I-Z-scheme CoFe₂O₄/BiVO₄/g-C₃N₄ heterojunction for enhanced peroxymonosulfate activation and levofloxacin degradation

This study presents the rational design of a magnetically recoverable CoFe 2 O 4 /BiVO 4 @g-C 3 N 4 (CFO/BVO@CN) ternary heterojunction for highly efficient levofloxacin (LVFX) degradation via peroxymonosulfate (PMS) activation under visible light. The key innovation lies in the synergistic integration of a unique charge transfer pathway with interfacial M-N (M = Co, Fe, Bi, V) chemical bonding, as unequivocally evidenced by XPS. This atomic-level interfacial engineering creates efficient electron channels that not only promote the spatial separation of photogenerated carriers but also dramatically accelerate the dual redox cycles of metal species (Co 2+ /Co 3+ , Fe 2+ /Fe 3+ ).Crucially, the V 4+ /V 5+ pair functions as an efficient electron shuttle, facilitating the rapid regeneration of PMS-active Co 2+ and Fe 2+ sites and sustaining a high-efficiency catalytic process. Consequently, the optimized system achieves an exceptional LVFX removal rate of 98.8% within 30 min, driven predominantly by singlet oxygen ( 1 O₂) and superoxide radicals ( • O 2 − ). The catalyst demonstrates robust stability over multiple cycles, facile magnetic separation, and effective detoxification of LVFX. This work provides a novel paradigm for developing multifunctional photocatalytic systems by marrying heterojunction engineering with atomic-level interface modulation for sustainable water purification.