Π-Bridge Modulations in D–π–A Conjugated Microporous Polymers to Facilitate Charge Separation and Transfer Kinetics for Efficient Photocatalysis

The burgeoning field of conjugated microporous polymers (CMPs) has generated widespread interest due to their potential as photocatalysts for hydrogen production from water. Nevertheless, their photocatalytic performance is sometimes hindered by inadequate charge separation and transfer, coupled with rapid charge recombination. Herein, a strategy to enhance photocatalytic performance via the customization of π-bridges through the modulation of heteroatoms in a series of donor-π-acceptor (D-π-A) CMPs is proposed. This affords optimized energy levels and improved charge separation and transfer, thus boosting photocatalytic efficiency. Among various heteroatom substitutions, S-doped CMP (10 mg) demonstrates the highest photocatalytic hydrogen evolution rate of 203 µmol h⁻¹ (AQY_450nm = 7.4%) under visible light irradiation. Subsequent experimental analysis reveals its superior photocatalytic performance can be largely related to its minimized exciton binding energy, facilitated charge transfer efficiency, and impeded charge recombination among these heteroatom-doped D-π-A CMPs. This research paves the way for the rational design and modification of organic semiconductors for advanced solar-driven photocatalysis by promoting charge separation and transfer.