Dual donor-acceptor covalent organic frameworks for hydrogen peroxide photosynthesis

• Main Authors: Qin, Chencheng, Wu, Xiaodong, Tang, Lin, Chen, Xiaohong, Li, Miao, Mou, Yi, Su, Bo, Wang, Sibo, Feng, Chengyang, Liu, Jiawei, Yuan, Xingzhong, Zhao, Yanli, Wang, Hou
• Other Authors: School of Chemistry, Chemical Engineering and Biotechnology
• Format: Article
• Language: English
• Published: 2023
• Subjects: Science::Chemistry; Photocatalysis; Photosynthesis
• Online Access: https://hdl.handle.net/10356/171530
• Institution: Nanyang Technological University

Constructing photocatalytically active and stable covalent organic frameworks containing both oxidative and reductive reaction centers remain a challenge. In this study, benzotrithiophene-based covalent organic frameworks with spatially separated redox centers are rationally designed for the photocatalytic production of hydrogen peroxide from water and oxygen without sacrificial agents. The triazine-containing framework demonstrates high selectivity for H2O2 photogeneration, with a yield rate of 2111 μM h-1 (21.11 μmol h-1 and 1407 μmol g-1 h-1) and a solar-to-chemical conversion efficiency of 0.296%. Codirectional charge transfer and large energetic differences between linkages and linkers are verified in the double donor-acceptor structures of periodic frameworks. The active sites are mainly concentrated on the electron-acceptor fragments near the imine bond, which regulate the electron distribution of adjacent carbon atoms to optimally reduce the Gibbs free energy of O2* and OOH* intermediates during the formation of H2O2.