Exciton Behavior Manipulated by Structural Isomers Governs H 2 O 2 Photosynthesis Pathway

作者：Shasha Liu, Chao Zhu, Haizhong Zhang, Jun Wang, Qile Fang, Chao Xu, Shuang Song, Yi Shen · 发表于：ACS Catalysis · 年份：2025 · DOI：10.1021/acscatal.5c07226 · 被引用次数：3 · 研究领域：Advanced Photocatalysis Techniques、Perovskite Materials and Applications、Covalent Organic Framework Applications

Solar-driven H 2 O 2 synthesis from water and oxygen holds great promise for environmentally benign and efficient chemical production. However, the complex photochemical pathways governed by exciton behavior during photoexcitation often limit both the yield and the selectivity of H 2 O 2 . Herein, structural isomers of the COFs ( p BPY-COF and o BPY-COF) are employed as probes to elucidate distinct exciton behaviors. Through precise structural engineering, exciton characteristics are finely tuned, revealing clear structure–activity relationship between intrinsic exciton behavior and photocatalytic performance. Comprehensive experimental and theoretical analyses demonstrate that the spatially twisted framework of p BPY-COF induces pronounced exciton effects, promoting energy-mediated singlet oxygen generation. This pathway competes with the oxygen reduction reaction, thereby constraining the H 2 O 2 production efficiency. In contrast, the planar-serrated structure of o BPY-COF enables ultrafast exciton dissociation, facilitating the efficient cooperative utilization of the compounds O 2 and H 2 O for H 2 O 2 synthesis. Remarkably, o BPY-COF achieves a production rate of 3637.8 μmol·h –1 ·g –1, with an apparent quantum yield (AQY) of 10.5% and a solar-to-chemical conversion efficiency (SCC) of 0.59%. By focusing on excited-state energy transfer, this work elucidates the pivotal role of distinct exciton-mediated reaction pathways in facilitating photocatalytic H 2 O 2 synthesis.