Polyaniline@g-C3N4 derived N-rich porous carbon for selective degradation of phenolic pollutants via peroxymonosulfate activation: An electron transfer mechanism

N-doped carbons have attracted extensive attention as catalysts for peroxymonosulfate (PMS) activation towards environmental remediation. However, synthesis of N-rich carbocatalysts is challenging and PMS activation mechanism is still unclear. Herein, novel N-rich porous carbocatalysts (C-PxCN-T) were synthesized by carbonization of polyaniline nanorods coated g-C3N4. C-P50CN-900 (polyaniline content 50%) calcined at 900 degrees C had high surface area (358 m2/g), product yield (27.1%) and N content (12.27 at%). It showed superior performance in activating PMS to degrade and mineralize various phenolic pollutants in a wide pH range (2-11) and with the co-existence of water constituents. A positive correlation was observed between phenol oxidation rates and contents of C--O, C-C/C--C and graphitic N, which served as active sites to facilitate adsorption of pollutants and PMS on C-P50CN-900 and subsequent electron-transfer from pollutants to PMS. Overall, this study provides new insights into rational design of N-doped carbocatalysts and elucidation of electron transfer pathway in PMS activation.