MOF-derived porous CoMn bimetallic oxide for efficient peroxymonosulfate activation: Electron transfer pathway transition steered by synergistic effect of nanoconfinement and bimetallic sites

The efficiency of peroxymonosulfate (PMS)-based advanced oxidation processes for eliminating persistent organic pollutants is significantly limited by high residual contaminant levels and complex aqueous matrices. Developing robust and environmentally benign catalysts that can activate PMS while resisting matrix interference is therefore critical for practical wastewater treatment. Herein, we present a porous Co Mn bimetallic oxide (p-Co 1.2 Mn 1.8 O 4 ) integrating dual-metal active sites with mesoporous nanoconfinement, which simultaneously enhances PMS adsorption energy and enriches interfacial pollutant concentration. A direct electron transfer process (ETP) was enabled between the tetracycline (TC) pollutant (as an electron donor) and surface-bound PMS complexes (PMS ⁎ , as an electron acceptor) on p-Co 1.2 Mn 1.8 O 4 . This synergy enables a novelty nonradical electron-transfer pathway (ETP) between tetracycline (electron donor) and surface-bound PMS complexes (PMS ⁎ , electron acceptor), achieved nearly 100 % removal of TC within 15 min and increasing the pseudo-first-order constant from 0.121 to 0.348 min −1 over the non-porous sample. The p-Co 1.2 Mn 1.8 O 4 /PMS system also efficiently degrades binary pollutants and maintains high activity under varied pH, temperature, and complex matrices. This work provides mechanistic insights into how multi-scale structural synergy—at both atomic and nanoscale levels—in bimetallic oxide catalysts regulates PMS activation, offering a promising platform for practical water purification.