Gao Zhi, Lv Sijia, Wang Yue, Xu Zhenzhen, Zong Yingtong, Tao Yuan, Zhao Yingji, Liu Xingyu, Yu Shuhui, Luo Mingbiao, Khaorapapong Nithima, Zhang Ruikang, Yamauchi Yusuke
Jiangxi Province Key Laboratory of Functional Organic Polymers, East China University of Technology, Nanchang, Jiangxi, 330013, China.
College of Chemistry and Chemical Engineering, Gannan Normal University, Ganzhou, Jiangxi, 341000, China.
Adv Sci (Weinh). 2024 Nov;11(43):e2406530. doi: 10.1002/advs.202406530. Epub 2024 Sep 27.
The interlayer stacking modes of 2D covalent-organic frameworks (COFs) directly influence their structural features, ultimately determining their functional output. However, controllably modulating the interlayer stacking structure in traditional 2D metal-free COFs, based on the same building blocks, remains challenging. Here, two trinuclear copper organic frameworks are synthesized successfully with different interlayer stacking structures: eclipsed AA stacking in Cu-PA-COF-AA and staggered ABC stacking in Cu-PA-COF-ABC, using the same monomers. Remarkably, various functionalities, including porosity and electronic and optical properties, can be effectively regulated by interlayer stacking. As a result, Cu-PA-COF-AA and Cu-PA-COF-ABC exhibit significantly different activities toward the photoreduction of U(VI), presenting a promising strategy for removing radioactive uranium pollution. Due to its broader visible-light absorption range and superior photogenerated carrier migration and separation efficiency, Cu-PA-COF-AA achieves a U(VI) removal ratio of 93.6% without additional sacrificial agents in an air atmosphere-≈2.2 times higher than that of Cu-PA-COF-ABC (42.0%). To the best of the knowledge, this is the first study to elucidate the effect of interlayer stacking in COFs on the photocatalytic activity of U(VI) reduction. This finding may inspire further exploration of the structure-function relationship in COFs as photocatalysts and their potential for photoinduced removal of radionuclides.
二维共价有机框架（COF）的层间堆积模式直接影响其结构特征，最终决定其功能输出。然而，基于相同的构建单元，可控地调节传统二维无金属COF中的层间堆积结构仍然具有挑战性。在此，使用相同的单体成功合成了两种具有不同层间堆积结构的三核铜有机框架：Cu-PA-COF-AA中的重叠AA堆积和Cu-PA-COF-ABC中的交错ABC堆积。值得注意的是，包括孔隙率、电子和光学性质在内的各种功能可以通过层间堆积有效地调节。结果，Cu-PA-COF-AA和Cu-PA-COF-ABC对U(VI)的光还原表现出显著不同的活性，为去除放射性铀污染提供了一种有前景的策略。由于其更宽的可见光吸收范围以及优异的光生载流子迁移和分离效率，Cu-PA-COF-AA在空气气氛中无需额外的牺牲剂即可实现93.6%的U(VI)去除率，约为Cu-PA-COF-ABC（42.0%）的2.2倍。据我们所知，这是第一项阐明COF中层间堆积对U(VI)还原光催化活性影响的研究。这一发现可能会激发对COF作为光催化剂的结构-功能关系及其光诱导去除放射性核素潜力的进一步探索。
