Quercetin sensitized covalent organic framework for boosting photocatalytic H₂O₂ production and antibacterial

In order to overcome the problems of narrow absorption spectrum, easy recombination of photogenerated carriers, and low solar energy utilization of single semiconductor photocatalysts, sensitization systems have been developed to further improve the efficiency of photocatalytic performance. However, the current sensitizers are mainly focused on relatively single dye molecules, which are easily decomposed during the photoreaction process. Therefore, the development of a novel sensitization system with high activity and stability is imminent. In this work, the natural compound Quercetin was used as a sensitizer to sensitized TAPPy-Da-COF. The Quercetin/TAPPy-Da-COF composites promoted rapid separation of photogenerated electron pairs and exhibited a broad visible-light response, which effectively improved the photocatalytic efficiency. The H₂O₂ yield of Quercetin/TAPPy-Da-COF in pure water is 289.84 μmol·h^-1·g^-1, which is 1.3 times higher than that of TAPPy-Da-COF. In addition, the reactive oxygen species (ROS) produced by photocatalysis under visible light had obvious antibacterial effects against Escherichia coli (E.coil) and Staphylococcus aureus (S.aureus). Meanwhile, At the same time, Quercetin/TAPPy-Da-COF/polyvinyl alcohol (PVA) aerogel was prepared by cross-linking method combined with freeze-drying method. It not only efficiently produced H₂O₂ and in-situ antimicrobial, but also realized rapid reuse of the catalyst. This work demonstrates that the natural compound Quercetin can be used as a sensitizer to sensitize semiconductor materials and promote the improvement of photocatalytic performance. This not only provides a new perspective for the subsequent development of green, efficient, and low-cost photosensitizers, but also offers a promising pathway for the synthesis of high-performance photocatalytic composites.