Dual Regulation of Charge Dynamics and Active Sites in Conjugated Porous Polymers for Efficient Photocatalytic H2 Production

Abstract

Organic polymers featuring donor−acceptor (D-A) molecular structures are promising photocatalysts for solar-driven H2 production. Unfortunately, most D-A-type polymeric photocatalysts still suffer from sluggish charge dynamics and deficient active sites. Herein, two organic porous polymers with different molecular structures are reported using triazine ring (Tz, A1) and dithieno[3,2-b:2′,3′-d]thiophene-S,S-dioxide (DTDO, A2) as acceptors. Compared to TPH-DTDO with the D-A structure, TTZ-DTDO possesses an extra charge transfer channel, more active sites, and stronger charge separation ability due to its A1-D-A2 structure, achieving the dual regulation of charge dynamics and active sites. These advantages enable TTZ-DTDO to realize an excellent H2 generation rate of 21.15 mmol h−1 g−1 under full arc light (320 nm < λ < 780 nm), which is approximately 5.5 times higher than that of TPH-DTDO (3.83 mmol h−1 g−1), demonstrating the positive influence of the A1-D-A2 molecular design on upgrading the photocatalytic efficiency of organic polymers.