Modulating donor-acceptor interactions in polymeric carbon nitride for efficient hydrogen peroxide photosynthesis and emerging contaminants removal

The molecular copolymerization of donor-acceptor (D-A) interactions has been effectively utilized to modulate the charge transfer dynamics in polymeric carbon nitride (PCN) photocatalysts, as demonstrated by recent studies. Herein, a D-A configured photocatalyst (TPCN) was constructed by copolymerizing 4,4’,4’’-(1,3,5-triazine-2,4,6-triyl) trianiline (TAPT) as the electron donor with triazine units (electron acceptor). The unique propeller structure of TAPT, combined with the triazine framework, expanded the π-conjugated system and induced a strong built-in electric field (BIEF) across the D-A configuration. Theoretical calculations and transient absorption spectroscopy revealed that this synergistic effect, arising from the expanded π-conjugated structure and the BIEF generated by D-A interactions, facilitated intramolecular charge separation and widened the range of light absorption, indicating accelerated charge transfer and suppressed recombination in TPCN. The optimized TPCN3 sample exhibited dramatically enhanced photocatalytic H2O2 production (1.74 mmol g−1 h−1), representing a 13.4-fold increase over pristine PCN. Additionally, the TPCN3 sample also exhibited significantly faster degradation kinetics than PCN counterpart toward various emerging contaminants.