Thiophene Functionalized Linear Conjugated Polymer toward High-Performance Photocatalytic H₂O₂ Production

Metal-free polymeric photocatalysts with tunable building blocks, ample redox-active centers, and exceptional light-harvesting capability have emerged as promising candidates for generating hydrogen peroxide (H 2 O 2 ) through the oxygen reduction reaction (ORR) and water oxidation reaction (WOR). The slow kinetics of the WOR process coupled with rapid charge recombination nevertheless impedes the efficient generation of H 2 O 2 . Herein, a thiophene functionalized linear conjugated polymer (DEB-Tp-S 2 ) was fabricated for effective overall H 2 O 2 photoproduction. DEB-Tp-S 2 exhibits a high initial photocatalytic H 2 O 2 yield rate of 2762 μmol g –1 h –1 in the absence of sacrificial additives and possesses outstanding cycling stability. Experimental and density functional theory (DFT) results exhibit that thiophene moieties can reduce the strength of the O–H bond in H 2 O, which promotes the 4e – WOR process, thereby suppressing charge recombination and improving proton supply. This work reveals the indispensable role of chemical structure engineering in polymer photocatalysts for optimizing their H 2 O 2 yield and offers fresh insights into the polymer design for achieving efficient H 2 O 2 production.