Orthogonal Configurative Spirobifluorene‐Based Conjugated Organic Polymers for Enhanced Water Oxidation Reaction to Boost H ₂ O ₂ Photosynthesis

Abstract Hydrogen peroxide (H 2 O 2 ) photosynthesis from water and oxygen catalyzed by polymer photocatalysts is highly desirable. However, as the rate‐determining step, the kinetically slower water oxidation reaction (WOR) limits H 2 O 2 production due to insufficient proton supply and reduced charge separation. A promising strategy is to boost WOR for enhanced hole consumption, thereby promoting charge separation and proton evolution to balance the proton demand for oxygen reduction reaction (ORR). Herein, the spirobifluorene, an efficient hole‐transporting material, is utilized as the building block for constructing conjugated organic polymers (COPs). The most efficient one, namely TBSF‐1, with lower exciton binding energy, stronger built‐in electric field, and prolonged excited state lifetime, achieved a rate of 9.29 mmol g −1 h −1 under air and pure water conditions, and a rate of 3.28 mmol g −1 h −1 under a nitrogen atmosphere. It also exhibited outstanding H 2 O 2 production across the pH range from acidic to alkaline conditions (pH = 3–11), with a maximum rate of 11.53 mmol g −1 h −1 at pH = 9. Furthermore, in a triphasic floating system, an accumulated H 2 O 2 concentration of 7.13 mmol L −1 within 12 h of irradiation is achieved. This work paves the way for the development of spirobifluorene‐based COPs in efficient H 2 O 2 photosynthesis.