Boosting peroxymonosulfate activation to mineralize organic pollutant by 2D defected CoMn bimetallic oxide catalyst through the enhanced non-radical pathway

Abstract

Here, we present a Co-Mn mixed oxide (Co4Mn1) with abundant defects to improve peroxymonosulfate (PMS) activation efficiency in catalytic bisphenol A (BPA) degradation. The degradation efficiency of BPA reached ∼100% within 3 min by the catalysis of Co4Mn1, and the catalyst showed superior catalytic activities over a broad pH range of 4.0 ∼ 11.0. Free radical scavenger experiment and electron spin resonance (ESR) analysis showed that singlet oxygen (1O2) acted as the dominant reactive oxygen species (ROS) for BPA degradation, while •SO4- and •OH radicals played an auxiliary role. Due to the construction of Co-O-Mn mixed bond and the defect structure, the Co4Mn1 catalyst possessed more oxygen vacancy and surface Mn4+ species, and therefore accelerated the BPA degradation by nonradical pathway significantly. This work highlights the important role of catalyst structure in ROS production during PMS activation and reaction pathway of BAP degradation, and furnishes theoretical support for the treatment of real wastewater by PMS oxidation.