Microwave and template assisted synthesis of atomically dispersed Co–N2 sites on carbon spheres for Fenton-like reaction

Abstract

Recently, single atomic metals supported on carbon materials have attracted great interests because of their high catalytic activity and stability in peroxymonosulfate (PMS)-based Fenton-like process. Herein, we propose a convenient strategy to synthesize Co single atoms supported on nitrogen-doped carbon spheres (Co@MNC) via microwave treatment. The microwave irradiation can simultaneously induce the formation of carbon defects and immobilize the Co single atoms in N doped carbon support in a few minutes. The obtained Co@MNC can activate PMS for efficient catalytic oxidation of organic pollutants. The radical quenching tests and electron paramagnetic resonance (EPR) verify that Co (IV)-oxo species, 1O2, and O2•− are responsible for the remediation of organic pollutants. Density functional theory (DFT) calculations confirm that unique and low coordinated Co–N2 on void or edge defects are favorable for PMS adsorption. The electrons will then transfer from Co atoms to adsorbed PMS via the bonded N. Co (IV)-oxo species and other ROSs are therefore generated for pollutants degradation. This work provides a fast method for the synthesis of single atom catalysts for efficient Fenton-like reactions.