Efficient degradation of Health-threatening organic pollutants in water by atomically dispersed Cobalt-Activated peroxymonosulfate

Abstract

Degrading health-threatening organic pollutants (HTOPs) in water systems through advanced oxidation processes (AOPs) is an effective way to treat environmental wastewater; however, such processes require advanced catalysts. This study combined complexation effects and structural confinement strategies to rapidly prepare Co2+-isolated metal–organic framework polymers and utilized a thermal treatment process to achieve the efficient anchoring of atom-dispersed Co in a boron–carbon-nitrogen matrix (denoted as SACoN/BCN), which can improve the utilization of Co catalytic sites. SACoN/BCN effectively activated peroxymonosulfate (PMS), with the ratio and mineralization rate of sulfamethazine (SMT) removed by degradation within 40 min reached 95.2 % and 70.0 %, respectively. Radical inhibition experiments and electron paramagnetic resonance (EPR) tests showed that 1O2 generated from SACoN/BCN-activated PMS was the key reactive oxygen species that promoted HTOP degradation. Density functional theory calculations revealed that, following the introduction of electron-deficient B heteroatoms, electrons in PMS will be injected into SACoN/BCN, thereby realizing strong adsorption and further activation of PMS. The cytotoxicity of SACoN/BCN is almost negligible because of the chemical bonding (or entrapment) of Co atoms in the inorganic boron–carbon-nitrogen matrix, thereby preventing Co from forming mobile CoII ions in the aqueous system. This research provides information for advanced catalysts for the removal of HTOPs and experimental and theoretical inspiration for the preparation of single-atom catalysts for advanced oxidation processes and the mechanism of PMS activation.