Optimizing Redox Centers Distribution in Benzothiadiazole‐Based Polymers for High‐Efficiency H ₂ O ₂ Photosynthesis in Pure Water

Abstract Hydrogen peroxide (H 2 O 2 ) photosynthesis by two‐electron oxygen reduction reaction (ORR) is a promising eco‐friendly approach. However, some intrinsic limitations of photocatalytic materials and constrained reaction environments hinder the improvement of catalytic performance. Conjugated polymer materials are widely studied as photocatalysts owing to their diverse building blocks and tunable electronic structures. In this study, hydrophobic benzothiadiazole (BT)‐based conjugated polymers with donor–acceptor (D–A) structures, namely TEPT‐BT, TEPB‐BT, and TEPN‐BT, are designed by changing the donor molecular center. In a pure water/air environment with TEPT‐BT, H 2 O 2 is efficiently produced at a rate of 2540.2 µmol g −1 h −1 . Density functional theory calculation results revealed that the triazine ring of 2,4,6‐tris(4‐ethynylphenyl)‐1,3,5‐triazine (TEPT) served as an additional electron acceptor other than BT. This feature endows TEPT‐BT with an optimal arrangement of redox centers, thereby enhancing exciton separation efficiency. Moreover, the triazine ring functioned as a powerful oxygen (O 2 ) adsorption site to promote H 2 O 2 photosynthesis under the synergistic effect of asymmetric dual ORR active sites. This study offers a promising approach for designing new hydrophobic D–A type conjugated polymer photocatalysts.