Dual-functional carbon nitride quantum dots as electron bridges and PMS activation sites on NH2-MIL-125(Ti) for malathion photocatalytic degradation

30CNQDs@NMT/PMS achieved almost complete degradation of malathion within 30 min simulated sunlight irradiation. • CNQDs was integrated successfully to promote the charge separation efficiency as electron bridges and enhance the adsorption energy of PMS for activation revealed by DFT. • •OH and •SO 4 – were generated to attack the identified sites of malathion computed via Fukui function. • The intermediate products in the photocatalytic process were less toxic than malathion assessed by T.E.S.T. Malathion, an organophosphate pesticide widely used in agricultural fields across the world, has raised environmental concerns due to its persistence and toxicity. Thus, a novel photocatalyst was synthesized by integrating carbon nitrogen quantum dots (CNQDs) onto NH 2 -MIL-125(Ti) (NMT) via a solid-phase thermal polycondensation method. It was demonstrated that CNQDs served a dual function as electron bridges to facilitate charge separation and as peroxymonosulfate (PMS) adsorption activation sites substantially enhancing the photocatalytic activity, which was revealed by Density Functional Theory (DFT). Under simulated sunlight, 30CNQDs@NMT achieved nearly 100 % malathion removal within 30 min via PMS activation, exhibiting 8.1 times higher than NMT. While •OH and •SO 4 – acted as the dominant reactive species to attack the malathion sites. The toxicity of the intermediate products assessed by T.E.S.T. (Toxicity Estimation Software Tool) were much lower than malathion. Moreover, 30CNQDs@NMT performed effectively in real water matrices, demonstrating its potential for practical environmental applications. Download: Download high-res image (233KB) Download: Download full-size image