Synergistic effect of confinement and photocatalysis-endowed adjustable peroxymonosulfate activation pathway to degrade antibiotics

This study firstly reported the regulation of PMS activation pathway via the novel catalyst (CQDs/Co@CN) that contained carbon quantum dots (CQDs) and confined nano Co dual active sites. CQDs/Co@CN showed superior catalytic activity for PMS activation due to the synergistic effect of CQDs and confined nano Co, and sulfamethoxazole degradation rate reached 0.661 min−1, which was even higher than that obtained by single atom catalyst. The reactive species in the system of CQDs/Co@CN/PMS could be easily regulated by the visible light. In the absence of visible light, PMS was mainly activated to produce Co(IV) = O, while it was activated to simultaneously produce radicals and Co(IV) = O in the presence of visible light. Moreover, the yields of Co(IV) = O increased by about 10 %. Experimental results and DFT calculation demonstrated that CQDs played crucial role in the regulation of reactive species. This study could provide a way to modulate the reactive species by visible light.