Multimetallic confined catalyst based on manganese ferrite and cobalt copper layered double hydroxide: enhanced peroxymonosulfate activation for sulfamethoxazole degradation via electronic synergistic effects and interfacial electron transfer pathways.

In this study, a MnFe2O4@CoCu-LDH composite catalyst (M1C2) with the synergistic effect of interfacial interaction and confinement was successfully constructed. In the M1C2/peroxymonosulfate (PMS) system, the degradation rate of 5 mg/L sulfamethoxazole (SMX) reached 90.67 ± 1.68%within 20 min. Mechanistic investigations revealed that PMS activation in this system was realized via a catalyst-mediated electron transfer pathway (CMETP). Moreover, the electronic synergy among multi-metal components facilitated efficient redox cycling, thus achieving the synergistic degradation of SMX by free radicals (SO4-, OH, O2-) and non-radical species (1O2). The degradation pathways were clarified by combining density functional theory (DFT) calculations with liquid chromatography-mass spectrometry (LC-MS) analysis. Toxicity simulation and rice germination experiments demonstrated a significant reduction in the ecological toxicity of degradation products, ensuring the safety of effluent discharge. This work provides a theoretical basis for the development of efficient and environmentally benign confined catalytic water treatment technologies.