Dual donor-acceptor covalent organic frameworks for hydrogen peroxide photosynthesis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37640726.
- Also identified by DOI 10.1038/s41467-023-40991-7 and PMC identifier 10462664.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
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 H<sub>2</sub>O<sub>2</sub> photogeneration, with a yield rate of 2111 μM h<sup>-1</sup> (21.11 μmol h<sup>-1</sup> and 1407 μmol g<sup>-1</sup> h<sup>-1</sup>) 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 O<sub>2</sub>* and OOH* intermediates during the formation of H<sub>2</sub>O<sub>2</sub>.