Covalent organic frameworks with imine proton acceptors for efficient photocatalytic H_(2) production  

作　　者：Xiaolin Liu Xiya Yang Xu Ding Hailong Wang Wei Cao Yucheng Jin Baoqiu Yu Jianzhuang Jiang 

机构地区：[1]Beijing Advanced Innovation Center for Materials Genome Engineering,Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials,Department of Chemistry and Chemical Engineering,School of Chemistry and Biological Engineering,University of Science and Technology Beijing,Beijing 100083,China [2]State Key Laboratory of NBC Protection for Civilian,Beijing 102205,China

出　　处：《Chinese Chemical Letters》2023年第10期265-269,共5页中国化学快报（英文版）

基　　金：financially supported by the Natural Science Foundation of China(Nos.22235001,22175020,22131005 and 21631003);Xiaomi Young Scholars Program;the Fundamental Research Funds for the Central Universities;University of Science and Technology Beijing;。

摘　　要：Covalent organic frameworks (COFs) are promising crystalline materials for the light-driven hydrogen evolution reaction (HER) due to their tunable chemical structures and energy band gaps.However,deeply understanding corresponding mechanism is still challenging due to the multiple components and complicated electron transfer and reduction paths involved in photocatalytic HER.Here,the photocatalytic HER investigation has been reported based on three COFs catalysts,1–3,which are prepared by benzo[1,2-b:3,4-b’:5,6-b’]trithiophene-2,5,8-trialdehyde to react with C3symmetric triamines including tris(4-aminophenyl)amine,1,3,5-tris(4-aminophenyl)benzene,and (1,3,5-tris-(4-aminophenyl)triazine,respectively.As the isostructural hexagonal honeycomb-type COF of 2 and 3 reported previously,the crystal structure of 1 has been carefully correlated through the powder X-ray diffraction study with the help of theoretical simulations.1 shows highly porous framework with Brunauer-Emmett-Teller surface area of1249 m^(2)/g.Moreover,the introduction of ascorbic acid into the photocatalytic system of COFs achieves the hydrogen evolution rate of 3.75,12.16 and 20.2 mmol g^(–1)h^(–1) for 1–3,respectively.The important role of ascorbic acid in photocatalysis of HER is disclosed to protonate the imine linkages of these COFs,leading to the obvious absorbance red-shift and the improved charge separation efficiency together with reduced resistance in contrast to pristine materials according to the spectroscopic and electronic characterizations.These innovations of chemical and physical properties for these COFs are responsible for their excellent photocatalytic performance.These results elucidate that tiny modifications of COFs structures is able to greatly tune their band structures as well as catalytic properties,therefore providing an available approach for optimizing COFs functionalities.

关 键 词：Covalent organic framework Photocatalysis Hydrogen evolution reaction Imine linkage PROTONATION 

分 类 号：TQ116.2[化学工程—无机化工] O643.36[理学—物理化学] O644.1[理学—化学]