Almost 100 % Peroxymonosulfate Conversion to Singlet Oxygen on Single‐Atom CoN2+2 Sites

Abstract

Single‐atom CoN 4 active sites have demonstrated excellent efficiency in peroxymonosulfate activation. However, the identification of CoN 4 active sites and the detailed singlet oxygen generation mechanism in peroxymonosulfate activation remains ambiguous. We demonstrate a strategy to regulate the generation of reactive oxygen species by atomically dispersed cobalt anchored on nitrogen‐doped carbon. As indicated by experiment and DFT calculations, CoN 2+2 was the active site and singlet oxygen was the predominant reactive oxygen species with a proportion of 98.89 %. Spontaneous dissociation of adsorbed peroxymonosulfate on the CoN 2+2 active sites was energetically unfavorable because of the weakly positive Co atoms and CoN 2+2 coordination, which directed PMS oxidation by a non‐radical pathway and with simultaneous singlet oxygen generation. The generated singlet oxygen degraded several organic pollutants with high efficiency across a broad pH range.