Substituent Effects on the Photocatalytic Properties of a Symmetric Covalent Organic Framework

作     者：Ting-Ting Liu Xin-Ping Wu Xue-Qing Gong 刘婷婷;吴新平;龚学庆

作者机构：Key Laboratory for Advanced Materials and Joint International Research Laboratory for Precision Chemistry and Molecular EngineeringFeringa Nobel Prize Scientist Joint Research CenterCentre for Computational Chemistry and Research Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China 

出 版 物：《Chinese Journal of Chemical Physics》 (化学物理学报（英文）)

年 卷 期：2022年第35卷第4期

页      面：647-654,I0062-I0085,I0150页

核心收录：

学科分类：081704[工学-应用化学] 081705[工学-工业催化] 07[理学] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 

基　　金：This work was supported by the National Key R&D Program of China(No.2018YFA0208602) the National Natural Science Foundation of China(No.21825301 and No.22003016) Shanghai Sailing Program(No.20YF1410000) Shanghai Municipal Science and Technology Major Project(No.2018SHZDZX03) Shanghai Science and Technology Committee(No.17520750100) 

主　　题：Covalent organic framework Photocatalysis Electronic structure Charge separation Density functional theory calculation 

摘      要：Symmetric covalent organic framework(COF)photocatalysts generally suffer from inefficient charge separation and short-lived photoexcited *** performing density functional theory(DFT)and time-dependent density functional theory(TDDFT)calculations,we find that partial substitution with one or two substituents(N or NH_(2))in the linkage of the representative symmetric COF(N_(0)-COF)gives rise to the separation of charge carriers in the resulting COFs(i.e.,N_(1)-COF,N_(2)-COF,(NH_(2))1-N_(0)-COF,and(NH_(2))2-N_(0)-COF).Moreover,we also find that the energy levels of the highest occupied crystal orbital(HOCO)and the lowest unoccupied crystal orbital(LUCO)of the N_(0)-COF can shift away from or toward the vacuum level,depending on the electron-withdrawing or electron-donating characters of the ***,we propose that partial substitution with carefully chosen electron-withdrawing or electron-donating substituents in the linkages of symmetric COFs can lead to efficient charge separation as well as appropriate HOCO and LUCO positions of the generated COFs for specific photocatalytic *** proposed rule can be utilized to further boost the photocatalytic performance of many symmetric COFs.