Tailored Band Gaps in Sulfur‐ and Nitrogen‐Containing Porous Donor–Acceptor Polymers

Donor–acceptor dyads hold the key to tuning of electrochemical properties and enhanced mobility of charge carriers, yet their incorporation into a heterogeneous polymer network proves difficulty owing to the fundamentally different chemistry of the donor and acceptor subunits. A family of sulfur‐ and nitrogen‐containing porous polymers (SNPs) are obtained via Sonogashira–Hagihara cross‐coupling and combine electron‐withdrawing triazine (C3N3) and electron‐donating, sulfur‐containing linkers. Choice of building blocks and synthetic conditions determines the optical band gap (from 1.67 to 2.58 eV) and nanoscale ordering of these microporous materials with BET surface areas of up to 545 m2 g−1 and CO2 capacities up to 1.56 mmol g−1. Our results highlight the advantages of the modular design of SNPs, and one of the highest photocatalytic hydrogen evolution rates for a cross‐linked polymer without Pt co‐catalyst is attained (194 μmol h−1 g−1). Catalysis in a SNP: Sulfur‐ and nitrogen‐containing porous polymers (SNPs) combine two key features for heterogeneous photocatalysts, namely an open pore structure and a modular, π‐conjugated backbone. The electronic and optical properties of these photoactive materials can be tuned by the choice of building blocks and via post‐synthetic doping.