Fe-MOF nanoparticles supported with carbon-defective g-C3N4 nanosheet as visible-light driven photo-Fenton catalyst for efficient degradation of tetracycline hydrochloride

The Fenton-like reaction has always been hampered by limitations related to its narrow pH range and poor stability. In this study, we successfully developed a novel catalyst composed of Prussian blue (PB) nanoparticles anchored onto carbon-defective g-C 3 N 4 (CD-C 3 N 4 ) nanosheets with a porous structure. Under visible light irradiation for 120 min, the removal efficiencies of tetracycline can achieve remarkably high removal rates as 93.3%. Significantly, this catalyst attains exceptional long-term stability enabling up to 20 cycles, while consistently maintaining a degradation efficiency exceeding 99%. Furthermore, this system exhibits a wide pH tolerance ranging from 3 to 9. Efficient charge separation and the introduction of carbon defects on the g-C 3 N 4 nanosheets contribute to the robust Fe 3+ /Fe 2+ cycles in PB, which support prolonged multiple recycles. ESR and quenching tests indicated that •O 2 − species play a significant role in catalytic degradation, with •OH and h + also being involved in the photo-Fenton reaction. Finally, we proposed potential photo-Fenton degradation pathways for tetracycline(TC) and conducted a comprehensive investigation into the toxicity changes of TC degradation through full-scale zebrafish toxicology assays. This work presents an innovative approach to construct highly stable Fenton-like catalysts through structural defect engineering combined with Fe-Metal organic frameworks(MOFs) loading strategies.