Construction of Covalent organic frameworks with bex topology for efficient photocatalytic hydrogen production

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 496; p. 153570
• Main Authors: Wang, Lin, Han, Changzhi, Pan, Jingwen, Li, Shuo, Jiang, Jia-Xing, Guo, Fengyun, Gao, Shiyong, Wang, Dongbo, Zhang, Yong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.09.2024
• Subjects: Bex Topology; Covalent organic frameworks; Photocatalytic Hydrogen Production; Covalent organic frameworks; Bex Topology; Photocatalytic Hydrogen Production
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.153570

Two pyrene-based bex topological COFs are reported for the first time for photocatalytic hydrogen generation. The HITMS-COF-11 showed the outstanding photocatalytic hydrogen evolution reaction (HER) rate of 25,000 μmol g−1 h−1, which is one of the best performances reported so far in the imine-based COFs and is also comparable with other type COFs. experiment and theoretical simulation confirmed that the pyrene-based bex topological COFs have broadened light absorption, improved photogenerated charge transfer and separation, and the enhanced hydrophilicity from the unsaturated amine groups in pyrene vertices. [Display omitted] •A novel bex topology option for COF-based photocatalysts.•HITMS-COF-11 exhibited an impressive photocatalytic HER rate of 25,000 umolg−1 h−1.•Uncondensed amino groups improved hydrophilicity and photovoltaic properties. Covalent organic frameworks (COFs) have become effective platforms for solar energy conversion and utilization. The rational design of the COF topology provides an effective strategy to expand the π-conjugation system and improve the photocatalytic activity. Herein, we have prepared two sub-stoichiometric pyrene-based 2D-COFs with the bex topology, HITMS-COF-10 and HITMS-COF-11, with high crystallinity and specific surface area. The HITMS-COF-11 exhibits an outstanding photocatalytic hydrogen evolution reaction (HER) rate of 25000 μmol g−1 h−1 in water under visible illumination (λ > 420 nm), demonstrating that the bex topological COFs could be one of the state-of-the-art photocatalyst candidates for hydrogen evolution and the importance of tuning the topological diversity at molecular levels for solar energy conversion and utilization.