Carbon nitride with grafted molecular as electron acceptor and active site to achieve efficient photo-activated peroxymonosulfate for organic pollutants removal.

The effective activation of peroxymonosulfate (PMS) by polymer carbon nitride (PCN) is hampered by the unpredictable movement and rapid recombination of photocarriers. In this study, niacin served as a beneficial modifier to help constructed the directional electron transfer pathway from the center to the edge in the synthesized PCN catalyst (UCNNA) for efficient PMS activation. The UCNNA/PMS/vis shows the highest kinetic constants (0.050 min−1), which is 2.9-fold increase over the PCN/PMS/vis. The experiments and theoretical calculations indicated that niacin as electron acceptor group prevents the recombination of photocarriers in-plane. Simultaneously, niacin can serve as PMS adsorption site, further facilitating electron transfer and the 1O 2 generation. Mass spectrometry analysis and Fukui index calculations confirm the priority of lateral chain oxidation (1O 2 attack site) during atrazine degradation. These results provide new insights into rational design of metal-free catalysts/PMS/vis system, as well as providing guidance and theoretical support for atrazine degradation mechanisms. [Display omitted] • The electron acceptor grafted PCN has been constructed by facile one-step thermopolymerization. • The electron acceptor nicotinic acid groups server as adsorption sites for PMS. • Electron transfer and 1O 2 in this system facilitate efficient degradation of ATZ. • The UCNNA/PMS/vis system has strong anti-interference ability. • The side chain of ATZ is preferentially attacked in this system. [ABSTRACT FROM AUTHOR]