Multiple path-dominated activation of peroxymonosulfate by MOF-derived Fe2O3/Mn3O4 for catalytic degradation of tetracycline

Sulfate radical-based advanced oxidation process (SR-AOP) has been identified as an efficient technology for the treatment of antibiotic contamination, with a focus on the development of catalysts for efficient activation of persulfate. In this work, a novel peroxymonosulfate (PMS) activator, metal organic framework (MOF) derived Fe2O3/Mn3O4 composite, was prepared and characterized. The physicochemical properties, catalytic performance of the catalyst and the degradation mechanism of tetracycline (TC) by the reaction system were thoroughly investigated. Combined with the experimental results and density functional theory (DFT) calculations, we can reasonably speculate that both radical (O2˙ˉ) and non-radical (1O2 and electron transfer) pathways contributed to the catalytic activation of PMS for TC degradation. The enhanced catalytic activity was attributed to the combination of Fe2O3 with Mn3O4 accelerated Fe(II)/Fe(III) cycle and Mn(II)/Mn(III) cycle. In addition, the extended peroxide O-O bond length facilitated the generation of 1O2. After five consecutive experiments, no significant change in catalytic performance and chemical structure was found, indicating that this catalyst had not only good chemical stability but also astonishing reusability. The research results are expected to provide some valuable theoretical basis for MOF-derived metal oxides catalytic activation of PMS for wastewater treatment.