Cu single atoms/O doping g-C3N4 mediated photocatalytic activation of peroxymonosulfate for ultrafast carbamazepine removal via high 1O2 yield

To facilitate the activation of peroxymonosulfate, it is useful to simultaneously tune the coordination environment of the single-atom catalyst and develop a structure that effectively exposes the active site. In this study, we used a pre-assembly calcination method to prepare a structure composed of Cu single atoms on O-doped g-C3N4 nanosheets (5Cu-OCN), and studied how this structure can effectively activate PMS under visible light catalysis. Compared to the g-C3N4, the 5Cu-OCN exhibits significantly improved PMS activation effect. Cu single atoms play an important role in catalyzing PMS activation and removing carbamazepine from solution, and explain the contribution of photo generated electrons and holes in enhancing the performance of catalysts in PMS activation. Furthermore, the constructive cooperation of 5Cu-OCN photocatalysts by PMS activation and photocatalysis has been shown to be useful in real aqueous systems. The results indicate that the main pathway for the generation of 1O2 is through the 5Cu-OCN photocatalytic process to promote PMS activation. In addition, the active reaction species involved in the degradation of carbamazepine were identified. This study provides an efficient copper monoatomic catalyst that can react to visible light for 1O2 based advanced oxidation processes.