Sun Chenglong, Han Ying, Guo Hongyu, Zhao Rui, Liu Youxing, Lin Zheng, Xiao Zehao, Sun Zongqiang, Luo Mingchuan, Guo Shaojun
School of Materials Science and Engineering, Peking University, Beijing, 100871, China.
Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology, Beijing, 100029, China.
Adv Mater. 2025 May;37(21):e2502990. doi: 10.1002/adma.202502990. Epub 2025 Mar 31.
The water oxidation reaction (WOR) with sluggish kinetics usually fails to adequately furnish protons to oxygen reduction reaction (ORR), which ultimately constrains the overall efficiency of photocatalytic synthesis of HO, particularly in the absence of sacrificial agents. Herein, a class of hydroxyl groups (─OH) functionalized covalent organic framework (COF) is reported as a proton reservoir to compensate ORR for greatly improving the efficiency of HO photosynthesis. It has been demonstrated that the incorporation of ─OH into the TFBP-DHBD (TFBP: 1,2,4,5-tetrakis-(4-formylphenyl)benzene, DHBD: 3,3'-dihydroxybenzidine) COF can achieve a 3.3 times higher HO photosynthetic activity than that of TFBP-BD (BD: benzidine) COF without ─OH groups. Isotope labeling experiments and in situ infrared spectroscopy analysis demonstrate that the proton reservoir can donate protons for ORR and subsequently regain the released protons from WOR. Theoretical calculations further confirm that the ─OH functionalized COF provides the protons for the formation of *OOH intermediate and reduces its energy barrier, thereby facilitating the photosynthesis of HO. A novel COF loaded with AlO spheres-based streamlined microreactor is built that can simultaneously achieve production of HO and elimination of bacteria over 1.3 × 10 CFU mL, superior to the reported continuous flow photocatalytic reactors.
动力学迟缓的水氧化反应（WOR）通常无法为氧还原反应（ORR）充分提供质子，这最终限制了光催化合成H₂O₂的整体效率，尤其是在没有牺牲剂的情况下。在此，报道了一类羟基（─OH）功能化的共价有机框架（COF）作为质子库来补偿ORR，从而极大地提高H₂O₂光合作用的效率。已证明，将─OH引入TFBP-DHBD（TFBP：1,2,4,5-四（4-甲酰基苯基）苯，DHBD：3,3'-二羟基联苯胺）COF中，其H₂O₂光合活性比不含─OH基团的TFBP-BD（BD：联苯胺）COF高3.3倍。同位素标记实验和原位红外光谱分析表明，质子库可以为ORR提供质子，随后从WOR中重新获得释放的质子。理论计算进一步证实，─OH功能化的COF为*OOH中间体的形成提供质子并降低其能垒，从而促进H₂O₂的光合作用。构建了一种基于Al₂O₃球的新型COF负载流线型微反应器，其可同时实现H₂O₂的生产和对超过1.3×10⁶ CFU mL细菌的消除，优于已报道的连续流光催化反应器。
