Z-scheme MIL-88A@LaFeO₃ heterojunction-enabled synergistic photo-Fenton system for acetamiprid degradation: mechanism and toxicity assessment

Acetamiprid (ACE) is a commonly used pesticide that threatens environmental health when leaching into aquatic environment, demanding urgent development of efficient and eco-friendly degradation technologies. Herein, a novel Z-scheme photo-Fenton catalyst (MIL-88A@LaFeO₃) was synthesized by doping LaFeO₃ into MIL-88A. Specifically, the optimized catalyst achieved 99.9 % ACE removal within 180 min under visible light and maintained 81.3 % efficiency after five cycles, demonstrating exceptional stability in real waters. Mechanistic investigations through electrochemical analysis and radical quenching experiments revealed that the Z-scheme charge transfer between LaFeO₃ and MIL-88A effectively suppressed electron-hole recombination while facilitated H₂O₂ activation to generate hydroxyl radicals (·OH). This process concurrently promoted Fe(III)/Fe(II) cycling to create a self-sustaining catalytic system, thereby enhancing the degradation of ACE. Notably, the degradation intermediates showed significantly reduced ecotoxicity compared to parent ACE. Overall, this study provides both a high-performance catalyst for pesticide remediation and fundamental insights into Z-scheme mechanisms, advancing technological innovation and practice in environmental remediation.