Teng Z, Zhang Z, Yang H, Zhang Q, Ohno T, Su C. Atomically isolated Sb(CN)
3 on sp
2-c-COFs with balanced hydrophilic and oleophilic sites for photocatalytic C-H activation.
SCIENCE ADVANCES 2024;
10:eadl5432. [PMID:
38295163 PMCID:
PMC10830113 DOI:
10.1126/sciadv.adl5432]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/29/2023] [Indexed: 02/02/2024]
Abstract
Activation of carbon-hydrogen (C-H) bonds is of utmost importance for the synthesis of vital molecules. Toward achieving efficient photocatalytic C-H activation, our investigation revealed that incorporating hydrophilic C≡N-Sb(CN)3 sites into hydrophobic sp2 carbon-conjugated covalent organic frameworks (sp2-c-COFs) had a dual effect: It simultaneously enhanced charge separation and improved generation of polar reactive oxygen species. Detailed spectroscopy measurements and simulations showed that C≡N-Sb(CN)3 primarily functioned as water capture sites, which were not directly involved in photocatalysis. However, the potent interaction between water molecules and the Sb(CN)3-modified framework notably enhanced charge dynamics in hydrophobic sp2-c-COFs. The reactive species ·O2- and ·OH (ad) subsequently combined with benzyl radical, leading to the formation of benzaldehyde, benzyl alcohol, and lastly benzyl benzoate. Notably, the Sb(CN)3-modified sp2-c-COFs exhibited a 54-fold improvement in reaction rate as compared to pristine sp2-c-COFs, which achieved a remarkable 68% conversion rate for toluene and an 80% selectivity for benzyl benzoate.
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