Strain effect of Co-Mn spinel oxides boosts efficient peroxymonosulfate activation for water decontamination

Lattice strain is commonly acknowledged as an effective strategy for tuning the catalytic activity of transition metals, yet its direct impact on Fenton-like reactions remains not fully understood. Herein, we introduce compressive strain into CoMn 2 O 4 via thermal expansion effects in conjunction with a component regulation strategy to enhance peroxymonosulfate (PMS)-based Fenton-like activation. Structural analysis reveals that the compressively strained features enhance metal-oxygen bond coupling and induces the formation of a substantial amount of oxygen vacancies, which promote PMS adsorption and interfacial charge transfer. The obtained CoMn 2 O 4 (2:1)/PMS system demonstrates efficient and stable removal of organic pollutants via dominant nonradical pathways ( 1 O 2 ), and the reaction kinetics was enhanced from 0.078 min −1 to 0.264 min −1 , and the removal rate for sulfadiazine (SD) was as high as 99.8% within 30 min after five cycles. Furthermore, the remarkable feasibility of the CoMn 2 O 4 (2:1)/PMS system for practical wastewater treatment in real river water and pharmaceutical effluents was demonstrated, particularly through the development of a catalytic membrane filtration system and an in-situ floating water treatment device. This study offers new insights into the design of high-performance PMS activation catalysts via lattice strain engineering.