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 Guoqiang Zhang;Yangsen Xu;Guoshuai Liu;Yongliang Li;Chuanxin He;Xiangzhong Ren;Peixin Zhang;Hongwei Mi

作者机构：College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen 518060China Guangdong Flexible Wearable Energy and Tools Engineering Technology Research Centre Shenzhen UniversityShenzhen 518060China Research Centre for Information TechnologyShenzhen Institute of Information TechnologyShenzhen 518172China School of Environmental and Civil EngineeringJiangnan UniversityWuxi 214122China 

出 版 物：《Chinese Chemical Letters》 (中国化学快报（英文版）)

年 卷 期：2023年第34卷第3期

页      面：546-552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：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) 

主　　题：Crystalline carbon nitride Exciton binding energy Built-in electric field Pyrimidine donor Excitons dissociation 

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.