Engineering an Asymmetric D ₁ ‐A‐D ₂ Architecture in Pyrrole‐Resorcinol Resins for Enhanced Charge Dynamics and Sustainable H ₂ O ₂ Photosynthesis

ABSTRACT The kinetics of H 2 O 2 synthesis on photocatalysts hinges critically on the dual capacity for efficient charge separation and favorable oxygen adsorption. Herein, we report the synthesis of a series of resins (PyRF, ThRF, and FuRF) with an asymmetric D 1 ‐A‐D 2 structure through molecular‐level modulation by incorporating strongly electron‐donating five‐membered heterocycles into the copolymerization of resorcinol‐formaldehyde resin (RF). Optical experiments reveal that constructing the asymmetric D 1 ‐A‐D 2 structures significantly enables a narrowed bandgap, reduces the charge‐transfer barriers, and enhances the electric field polarization gradient, thereby enabling improved separation of photogenerated carriers. In situ infrared spectroscopy spectrum and density functional theory calculations confirm that the incorporation of pyrrolic N provides an active site for the oxygen reduction reaction (ORR) with a lower energy barrier. The PyRF resin exhibits remarkable activity for photocatalytic H 2 O 2 production with a generation rate of 2806.3 µmol g − 1 h − 1 without a sacrificial agent, representing a 5.3‐fold enhancement over the pristine RF resin. It also achieves a high H 2 O 2 selectivity of 85%, an apparent quantum yield (AQY) of 15.6% at 420 nm, surpassing most phenol‐formaldehyde resin‐based photocatalysts. This study achieves optimization of the electronic properties of organic polymer photocatalysts, providing groundbreaking insights for the sustainable development of H 2 O 2 photocatalytic systems.