Catalytic activation of peroxymonosulfate by Mn/N co-doped porous carbon for effective phenol degradation: crucial role of non-radical pathways

In the degradation process of organic pollutants, compared with the free radical pathway, the non-radical pathway shows the advantages of mild oxidation ability, strong anti-interference, and adaptation to different pH values. In this study, a manganese–nitrogen co-doped porous carbon (Mn–N@C-1) with high nitrogen content was prepared to improve the contribution rate of non-radical pathways to the degradation process of organic pollutants. The high performance of Mn–N@C-1 is attributed to the formation of Mn–Nx sites between Pyridine N and Mn, which can effectively oxidize organic pollutants in water (phenol, bisphenol A, 2,4-dichlorophenol). In addition, the catalyst exhibits high catalytic activity over a wide pH range (pH = 3–9) and has good immunity to inorganic anions. Moreover, the Mn–Nx site and graphitic-N are considered to be the generation sites of singlet oxygen, and the role of metastable Mn–N@C-1/PMS* complexes in the electron transfer process is explored. Overall, this study explores the crucial role of non-radical pathways in the degradation of organic pollutants by carbon-based materials.