Driving hydrogen peroxide artificial photosynthesis and utilization for emerging contaminants removal by cyanided polymeric carbon nitride

To unravel the influence of the structure-activity relationship (SAR) of cyano (-CN) groups on the photocatalytic activity of polymeric carbon nitride (PCN), -CN groups were controllably introduced and finely regulated within the PCN framework in this study. The SAR between the -CN contents and hydrogen peroxide (H2O2) artificial photosynthesis performance was conclusively confirmed. Comprehensive experimental characterization and theoretical calculations demonstrated that the introduced -CN accelerated the dissociation of excitons to free charge carriers. The excitons dissociation efficiency was enhanced twofold, and the adsorption and activation of O2 molecules were strengthened, driving the two-electron O2 reduction reaction (2e- ORR) to produce H2O2. Importantly, the on-site generation of abundant reactive oxygen species during 2e- ORR by the cyanided PCN photocatalyst demonstrated its outstanding performance for the removal of multifarious emerging contaminants (ECs), including 4-hydroxybenzoic acid, aspirin, and ibuprofen, to realize sustainable water purification.