中国科学院上海有机化学研究所赵新团队报道了偶氮苯桥联共价有机框架促进碱性水光催化生产过氧化氢——一个原子导致的显著提高。相关研究成果发表在2024年8月13日出版的《德国应用化学》。

共价有机框架（COFs）已被证明是生产过氧化氢（H₂O₂）的有前景的光催化剂。然而，构建具有新活性位点、高光活性和宽范围光吸收的COFs以高效生产H₂O₂仍然具有挑战性。

该文介绍了一种新型偶氮苯桥联2D COF（COF-TPT-Azo）的合成，其在碱性条件下具有优异的光催化H₂O₂生产性能。值得注意的是，尽管COF-TPT-Azo与其相应的亚胺连接对应物（COF-TPT-TPA）仅相差一个原子（-N=N-vs.-C=N-），但COF-TPT-Azo具有明显更窄的带隙、增强的电荷传输和促进的光活性。

值得注意的是，当用作无金属光催化剂时，COF-TPT-Azo在pH=11时的光催化H₂O₂生产率高达1498μmol g^-1 h^-1，是COF-TPT-TPA的7.9倍。进一步的密度泛函理论（DFT）计算表明，-N=N-键是光催化的活性位点。

该项工作为开发高性能COF基光催化剂提供了新的前景。

附：英文原文

Title: Azobenzene-bridged Covalent Organic Frameworks Boosting Photocatalytic Hydrogen Peroxide Production from Alkaline Water: One Atom Makes a Significant Improvement

Author: Hui-Hui Sun, Zhi-Bei Zhou, Yubin Fu, Qiao-Yan Qi, Zhen-Xue Wang, Shunqi Xu, Xin Zhao

Issue&Volume: 2024-08-13

Abstract: Covalent organic frameworks (COFs) have been demonstrated as promising photocatalysts for hydrogen peroxide (H2O2) production. However, the construction of COFs with new active sites, high photoactivity, and wide-range light absorption for efficient H2O2 production remains challenging. Herein, we present the synthesis of a novel azobenzene-bridged 2D COF (COF-TPT-Azo) with excellent performance on photocatalytic H2O2 production under alkaline conditions. Notably, although COF-TPT-Azo differs by only one atom (-N=N- vs. -C=N-) from its corresponding imine-linked counterpart (COF-TPT-TPA), the COF-TPT-Azo exhibits a significantly narrower band gap, enhanced charge transport, and prompted photoactivity. Remarkably, when employed as a metal-free photocatalyst, COF-TPT-Azo achieves a high photocatalytic H2O2 production rate up to 1498 μmol g-1 h-1 at pH =11, which is 7.9 times higher than that of COF-TPT-TPA. Further density functional theory (DFT) calculations reveal that the -N=N- linkages are the active sites for photocatalysis. This work provides new prospects for developing high-performance COF-based photocatalysts.

DOI: 10.1002/anie.202409250

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202409250