Molecular Engineering in D-π-A-A-Type Conjugated Microporous Polymers for Boosting Photocatalytic Hydrogen Evolution

Conjugated microporous polymer (CMP) photocatalysts with donor-π-acceptor (D-π-A) or donor-acceptor (D-A) structures have garnered great attention for solar-driven hydrogen generation because of their inherent charge separation nature and high surface area. Herein, we design a series of D-π-A-A-type CMP photocatalysts to uncover the influence of the content of the dibenzo[b,d]thiophene-S-S-dioxide (BTDO) acceptor on the photocatalytic activity. The results demonstrate that the acceptor content in the D-π-A-A-type CMP photocatalysts affects the electronic structure, the availability of reaction sites, and the separation between light-generated electrons and holes, which mainly determine the photocatalytic performance for H₂ release. Benefiting from the synergy of light absorption, hydrophilicity, and active sites, the bare polymer PyT-BTDO-2 with an optimized BTDO content exhibits a high H₂ production rate of 230.06 mmol h^-1 g^-1 under simulated sunlight, manifesting that the strategy of D-π-A-A structural design is efficacious for boosting the photocatalytic performance of CMP photocatalysts.