Wu Shuhong, Li Chao, Wang Ying, Zhuang Yan, Pan Yi, Wen Na, Wang Shuo, Zhang Zizhong, Ding Zhenxin, Yuan Rusheng, Dai Wenxin, Fu Xianzhi, Long Jinlin
State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, 350108, P. R. China.
College of Materials Science and Engineering, Fuzhou University, Fuzhou, 350108, P. R. China.
Angew Chem Int Ed Engl. 2023 Sep 4;62(36):e202309026. doi: 10.1002/anie.202309026. Epub 2023 Jul 27.
The keto-switched photocatalysis of covalent organic frameworks (COFs) for efficient H evolution was reported for the first time by engineering, at a molecular level, the local structure and component of the skeletal building blocks. A series of imine-linked BT-COFs were synthesized by the Schiff-base reaction of 1, 3, 5-benzenetrialdehyde with diamines to demonstrate the structural reconstruction of enol to keto configurations by alkaline catalysis. The keto groups of the skeletal building blocks served as active injectors, where hot π-electrons were provided to Pt nanoparticles (NPs) across a polyvinylpyrrolidone (PVP) insulting layer. The characterization results, together with density functional theory calculations, indicated clearly that the formation of keto-injectors not only made the conduction band level more negative, but also led to an inhomogeneous charge distribution in the donor-acceptor molecular building blocks to form a strong intramolecular built-in electric field. As a result, visible-light photocatalysis of TP-COFs-1 with one keto group in the skeletal building blocks was successfully enabled and achieved an impressive H evolution rate as high as 0.96 mmol g h . Also, the photocatalytic H evolution rates of the reconstructed BT-COFs-2 and -3 with two and three keto-injectors were significantly enhanced by alkaline post-treatment.
通过在分子水平上设计骨架结构单元的局部结构和组成，首次报道了用于高效析氢的共价有机框架（COF）的酮基转换光催化。通过1,3,5-苯三甲醛与二胺的席夫碱反应合成了一系列亚胺连接的BT-COF，以证明通过碱催化烯醇到酮构型的结构重构。骨架结构单元的酮基作为活性注入剂，通过聚乙烯吡咯烷酮（PVP）绝缘层向铂纳米颗粒（NP）提供热π电子。表征结果与密度泛函理论计算一起清楚地表明，酮注入剂的形成不仅使导带能级更负，而且导致供体-受体分子结构单元中的电荷分布不均匀，从而形成强的分子内内置电场。结果，成功实现了骨架结构单元中含有一个酮基的TP-COF-1的可见光光催化，并实现了高达0.96 mmol g h 的令人印象深刻的析氢速率。此外，通过碱后处理，具有两个和三个酮注入剂的重构BT-COF-2和-3的光催化析氢速率显著提高。
