Structural engineering in ternary conjugated microporous polymers by regulating the acceptor position for boosting photocatalytic hydrogen production

Conjugated microporous polymers (CMPs) as photocatalysts have been widely researched due to their remarkable surface area and design flexibility. In this study, through the regulation strategy of acceptor location, we designed and synthesized D₁-D₂-A structured TPE-TH-BTDO and D₁-A-D₂ structured TPE-BTDO-TH CMPs using TPE and TH as donors (D), and BTDO as acceptor (A). Compared with D₁-D₂-A-type TPE-TH-BTDO, D₁-A-D₂ structured TPE-BTDO-TH achieves a higher H₂ production rate of 52.71 mmol g⁻¹ h⁻¹ (λ > 420 nm), approximately 2.12 times that of TPE-TH-BTDO. Different from D₁-D₂-A system, the D₁-A-D₂ architecture enables the dual donor to push electrons toward the central acceptor, forming bidirectional directional charge transfer (D₁ → A ← D₂), resulting in the accumulation of photogenerated electrons on the acceptors, and suppressing electron-hole recombination due to the enhanced intramolecular built-in electric field and the short-distance transport. These discoveries reveal the importance of structure design in controlling charge separation and transport in conjugated microporous polymers for boosting photocatalytic hydrogen production.