Covalent organic frameworks (COFs) have emerged as promising candidates for solar-driven photosynthesis of hydrogen peroxide (H₂O₂), yet the development of high-performance COFs tailored for practical applications presents substantial challenges. This research introduces the integration of the redox-active catechol moiety into a series of COFs (TPE-COF-OH, TPB-COF-OH, and TPP-COF-OH), serving as the pivotal active site for photocatalytic oxygen (O₂) reduction to H₂O₂ through a reversible catechol-quinone interconversion mechanism. This process facilitates the transformation of catechol to o-benzoquinone in the presence of molecular O₂, while photoexcited electrons are utilized to revert o-benzoquinone to catechol, reducing the energy barrier for H₂O₂ synthesis. Notably, TPB-COF-OH demonstrates an unparalleled H₂O₂ production rate of 6608 μmol h^–1 g^–1, outperforming its molecular counterpart, TPB-COF-OMe, which lacks the redox-active catechol unit. Furthermore, TPB-COF-OH achieves a solar-to-chemical conversion efficiency of 0.84%, marking the highest value among COF-based photocatalysts in solar-driven H₂O₂ production. This investigation not only underscores the critical role of molecular engineering in enhancing COF performance but also broadens the horizon for solar-to-chemical energy conversion technologies.

中文翻译：

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合理设计具有氧化还原活性儿茶酚部分的共价有机框架，以实现过氧化氢的高性能整体光合作用


共价有机框架（COF）已成为太阳能驱动的过氧化氢（H ₂ O ₂ ）光合作用的有前途的候选者，但针对实际应用定制的高性能COF的开发提出了巨大的挑战。这项研究引入了将氧化还原活性儿茶酚部分整合到一系列COF（TPE-COF-OH、TPB-COF-OH和TPP-COF-OH）中，作为光催化氧的关键活性位点（O < b2> ) 通过可逆儿茶酚-醌互变机制还原为 H ₂ O ₂ 。该过程在 O ₂ 分子存在的情况下促进儿茶酚转化为邻苯醌，同时利用光激发电子将邻苯醌还原为儿茶酚，从而降低 H ₂ O ₂ 合成。值得注意的是，TPB-COF-OH 表现出无与伦比的 H ₂ O ₂ 生产率，达到 6608 μmol h ^–1 g ^–1 ，优于其分子对应物 TPB-COF-OMe，缺乏氧化还原活性儿茶酚单元。此外，TPB-COF-OH的太阳能-化学转化效率达到0.84%，标志着COF基光催化剂在太阳能驱动的H ₂ O ₂ 生产中的最高值。这项研究不仅强调了分子工程在提高 COF 性能方面的关键作用，而且拓宽了太阳能到化学能转换技术的视野。