Pyrimidine donor induced built-in electric field between melon chains in crystalline carbon nitride to facilitate excitons dissociation  

作　　者：Guoqiang Zhang Yangsen Xu Guoshuai Liu Yongliang Li Chuanxin He Xiangzhong Ren Peixin Zhang Hongwei Mi 

机构地区：[1]College of Chemistry and Environmental Engineering,Shenzhen University,Shenzhen 518060,China [2]Guangdong Flexible Wearable Energy and Tools Engineering Technology Research Centre Shenzhen University,Shenzhen 518060,China [3]Research Centre for Information Technology,Shenzhen Institute of Information Technology,Shenzhen 518172,China [4]School of Environmental and Civil Engineering,Jiangnan University,Wuxi 214122,China

出　　处：《Chinese Chemical Letters》2023年第3期546-552,共7页中国化学快报（英文版）

基　　金：jointly supported by the Natural Science Foundation of China(Nos.51874199,22078200,22102103);the grant from SZIIT(No.SZIIT2022KJ026);Guangdong Basic and Applied Basic Research Foundation(Nos.2019A1515111021,2021A1515010162);Shenzhen Innovation Program(No.JCYJ20170818142642395)。

摘　　要：The strong intrinsic Coulomb interactions of Frenkel excitons in crystalline carbon nitride(CCN) greatly limits their dissociation into electrons and holes, resulting in unsatisfactory charges separation and photocatalytic efficiency. Herein, we propose a strategy to facilitate excitons dissociation by molecular regulation induced built-in electric field(BIEF). The electron-rich pyrimidine-ring into CCN changes the charge density distribution over heptazine-rings to induce BIEF between melon chains. Such BIEF is sufficient to overcome the considerable exciton binding energy(EBE) and reduce it from 38.4 meV to 16.4 meV,increasing the excitons dissociation efficiency(EDE) from 21.5% to 51.9%. Our results establish a strategy to facilitate excitons dissociation through molecular regulation induced BIEF, targeting the intrinsic high EBE and low EDE of polymer photocatalysts.

关 键 词：Crystalline carbon nitride Exciton binding energy Built-in electric field Pyrimidine donor Excitons dissociation 

分 类 号：O643.36[理学—物理化学] O644.1[理学—化学]