无序碳单层的电子结构及氢原子吸附的第一性原理研究  

First-principles study on the electronic structure and hydrogen-adsorption properties of amorphous carbon monolayers

作　　者：张颖 刘佳溪 孙志海 黄强 夏永鹏 李彬 邹勇进[1,2] 张焕芝 黄鹏儒[1,2] 徐芬 孙立贤 ZHANG Ying;LIU Jia-Xi;SUN Zhi-Hai;HUANG Qiang;XIA Yong-Peng;LI Bin;ZOU Yang-Jin;ZHANG Huan-Zhi;HUANG Peng-Ru;XU Fen;SUN Li-Xian(School of Materials Science and Engineering,Guilin University of Electronic Technology,Guangxi Key Laboratory of Information Materials,Guilin 541004,China;Guangxi Collaborative Innovation Center for Structure-Efficiency Relationships of New Energy Materials,Guilin 541004,China)

机构地区：[1]桂林电子科技大学材料科学与工程学院广西信息材料重点实验室,桂林541004 [2]广西新能源材料构效关系协同创新中心,桂林541004

出　　处：《原子与分子物理学报》2022年第4期24-32,共9页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(51801041,551671062,5187011196,51971068);国家重点研究开发计划(018YFB1502103,2018YFB1502105);广西自然科学基金(2017JJB150085);广西科技计划(2018AD19052);桂林电子科技大学研究生教育创新计划项目(2020YCXS111)。

摘　　要：本研究运用第一性原理计算方法,系统地研究了无序碳单层材料不同位点的电子结构及其析氢性能.计算结果显示无序结构中的C-C键相比于石墨烯中的C-C键在26.7%的范围内有不同程度的拉伸或压缩,使得C原子电荷在-0.17~+0.16个电子范围内变化,导致部分C原子电子局域化.电子的局域化增强了C原子的化学活性,从而表现出了较强的吸附性能.我们发现H原子与C原子的键合及析氢性能与C原子间的键角相关.对于三配位的碳原子,其中三个价电子通过sp^(2)杂化轨道与最邻近的碳原子结合形成较强的共价键,而余下的一个p^(z)轨道电子可以与H原子在垂直于原子层的方向形成较弱的化学键.无序结构可以打破三个sp^(2)杂化轨道的对称性,进而影响p^(z)轨道与氢的成键.本研究在一定程度上揭示了单层无序碳材料结构-性能的构效关系,为实验上设计特定性能的无序碳功能材料提供理论指导.First-principles calculations were performed to systematically study the electronic structure and hydrogen evolution properties of the amorphous carbon monolayers.Our results show that compared with a pristine graphene,the C-C bonds in the disordered structure undergo different degrees of stretching or compression within 26.7%.The atomic charge of C atoms changes in the range of-0.17~+0.16 electrons,resulting in electron localization on some C atoms.The localization of electrons enhances the chemical activity of the C atoms and hence the adsorption to alien atoms.The bonding of H atom with C atom and the hydrogen evolution performance were found to be correlated with the bond angles of the C atoms.For a triple-coordinate carbon atom,three valence electrons combine strongly with the nearest carbon atom through the sp^(2) hybridization and the remaining p^(z) orbital electron being unbonded.This electron could bond with adsorbates with relatively weak bonding.The symmetry of the three sp^(2) hybrid orbitals is broken by the disordered structure,which affects the bonding between the p^(z) orbitals and hydrogen.We found that the adsorption strength of this bond could be modified by tuning the angles of C-C bonds.Our results could provide deep insight into the correlation of structures and properties of amorphous carbon monolayer.

关 键 词：第一性原理计算 无序碳 电子性质 氢吸附 析氢反应 

分 类 号：O643[理学—物理化学]