Forming electron traps deactivates self-assembled crystalline organic nanosheets toward photocatalytic overall water splitting  

形成电子陷阱导致自组装晶态有机纳米片光催化全解水性能失活研究

作　　者：Lei Wang Jia Liu Haiyun Wang Hao Cheng Xiaojun Wu Qun Zhang Hangxun Xu 王磊;刘佳;王海云;程浩;武晓君;张群;徐航勋(Hefei National Laboratory for Physical Sciences at the Microscale,CAS Key Laboratory of Soft Matter Chemistry,Department of Polymer Science and Engineering,University of Science and Technology of China,Hefei 230026,China;Hefei National Laboratory for Physical Sciences at the Microscale,Synergetic Innovation Center of Quantum Information and Quantum Physics,Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China;Hefei National Laboratory for Physical Sciences at the Microscale,CAS Key Laboratory of Materials for Energy Conversion,Department of Materials Science and Engineering,and CAS Center for Excellence in Nanoscience,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]Hefei National Laboratory for Physical Sciences at the Microscale,CAS Key Laboratory of Soft Matter Chemistry,Department of Polymer Science and Engineering,University of Science and Technology of China,Hefei 230026,China [2]Hefei National Laboratory for Physical Sciences at the Microscale,Synergetic Innovation Center of Quantum Information and Quantum Physics,Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China [3]Hefei National Laboratory for Physical Sciences at the Microscale,CAS Key Laboratory of Materials for Energy Conversion,Department of Materials Science and Engineering,and CAS Center for Excellence in Nanoscience,University of Science and Technology of China,Hefei 230026,China

出　　处：《Science Bulletin》2021年第3期265-274,M0004,共11页科学通报（英文版）

基　　金：the National Key R&D Program of China(2017YFA0207301,2016YFA0200602,and 2018YFA0208702);the National Natural Science Foundation of China(21875235,21573211,and 21633007);the Anhui Initiative in Quantum Information Technologies(AHY090200);the China Postdoctoral Science Foundation(BX20200317);the Fundamental Research Funds for the Central Universities。

摘　　要：Most biological photoredox reactions occur in sophisticated molecular assemblies consisting of highly organized light-harvesting moieties and catalytic centers.Mimicking these prototypes by creating supramolecular assemblies could be a potentially viable approach toward artificial photosynthesis.Although self-assembled organic materials are known to carry out water splitting reactions,developing self-assembled organic materials for photocatalytic overall water splitting still remains a critical challenge.Herein,we first demonstrate that crystalline organic nanosheets assembled from linear oligo(phenylene butadiynylene)(OPB)are able to catalyze overall water splitting under visible light irradiation.Further investigations reveal that the photocatalytic activity of self-assembled organic structures is closely related to the crystalline structure along with the corresponding electronic structure.Structural disorders in OPB nanosheets and extrinsic factors such as adsorbed water molecules will induce the formation of electron traps which can make the OPB nanosheets thermodynamically unfavorable for photocatalytic overall water splitting.The deactivation mechanism unveiled in this study provides crucial insights into the assembling of artificial organic materials for future solar-to-chemical energy conversion.许多自然界生物体内的光化学反应在由吸光单元和催化活性中心构成的复杂有序的分子组装体内发生.通过构造超分子组装材料来模仿自然界光化学反应过程是实现人工光合成的潜在途径.迄今为止,已经有许多自组装有机材料被发展起来用于光催化分解水反应研究,然而能够实现光催化全解水的自组装有机材料尚未见诸于报道.本文首先合成了一种能够在可见光照射下催化全解水的自组装晶态有机纳米片.进一步研究表明自组装晶态有机纳米片的光催化性能与其组装结构密切相关.当其晶态结构被破坏或者表面吸附水分子时,会在能带结构内形成电子陷阱从而导致其在热力学上不再满足全解水要求而失去光催化活性.这项研究为将来设计和合成用于太阳能到化学能转换的自组装有机材料提供了新的思路与见解.

关 键 词：Self-assembly Water splitting PHOTOCATALYSIS Conjugated polymers DEACTIVATION 

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]