Regulation of reactive oxygen species generation by graphitization and defect degree of Co-loaded carbon in peroxymonosulfate activation

The designing of functional groups and structured active sites is a vital strategy for efficient Peroxymonosulfate (PMS)-based advanced oxidation processes (PMS-AOPs). However, the regulation mechanism and correlation of graphitization/defect degree and reactive oxygen species (ROS) are still not fully understood for a composite catalyst. Herein, a family of metal–organic framework (MOF)-derived cobalt-nitrogen-carbon with different graphitization/defect degrees was designed and synthesized successfully to activate PMS for carbamazepine (CBZ) degradation. NC-0.6/PMS system exhibited efficient performance for several contaminants, but NC-10/PMS system preferred to remove contaminants with low electrophilicity. The correlation analysis and Fukui index calculation revealed that high graphitization and low defect degree of catalysts stimulated diverse ROS generation ( • OH and 1 O 2 ) and the decreasing of graphitization was beneficial to form a single 1 O 2 oxidation system. The regulation of ROS was a potential approach for the selective removal of contaminants. This work provides a new insight into the mechanism transformation of ROS-oriented degradation of pollutants in PMS-AOPs.