Keto-anthraquinone covalent organic framework for H<sub>2</sub>O<sub>2</sub> photosynthesis with oxygen and alkaline water.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38531862.
- Also identified by DOI 10.1038/s41467-024-47023-y and PMC identifier 11258313.
- 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
Hydrogen peroxide photosynthesis suffers from insufficient catalytic activity due to the high energy barrier of hydrogen extraction from H<sub>2</sub>O. Herein, we report that mechanochemically synthesized keto-form anthraquinone covalent organic framework which is able to directly synthesize H<sub>2</sub>O<sub>2</sub> (4784 μmol h<sup>-1</sup> g<sup>-1</sup> at λ > 400 nm) from oxygen and alkaline water (pH = 13) in the absence of any sacrificial reagents. The strong alkalinity resulted in the formation of OH<sup>-</sup>(H<sub>2</sub>O)<sub>n</sub> clusters in water, which were adsorbed on keto moieties within the framework and then dissociated into O<sub>2</sub> and active hydrogen, because the energy barrier of hydrogen extraction was largely lowered. The produced hydrogen reacted with anthraquinone to generate anthrahydroquinone, which was subsequently oxidized by O<sub>2</sub> to produce H<sub>2</sub>O<sub>2</sub>. This study ultimately sheds light on the importance of hydrogen extraction from H<sub>2</sub>O for H<sub>2</sub>O<sub>2</sub> photosynthesis and demonstrates that H<sub>2</sub>O<sub>2</sub> synthesis is achievable under alkaline conditions.