化学学报 ›› 2017, Vol. 75 ›› Issue (3): 284-292.DOI: 10.6023/A16110645 上一篇    下一篇

研究论文

基于缺陷曲率对含有V1~V4空位(5,5)单壁碳纳米管[1+1]和[2+1]加成反应的第一性原理研究

李磊a, 贾桂霄a,b, 王晓霞a, 吴铜伟a, 宋希文a,b, 安胜利a,b   

  1. a 内蒙古科技大学材料与冶金学院 包头 014010;
    b 内蒙古自治区新型功能陶瓷与器件重点实验室 包头 014010
  • 收稿日期:2016-11-29 修回日期:2017-02-13 出版日期:2017-03-15 发布日期:2017-02-13
  • 通讯作者: 贾桂霄,E-mail:guixiao.jia@163.com E-mail:guixiao.jia@163.com
  • 基金资助:

    项目受内蒙古自然科学基金(No.2016MS0513)和内蒙古科技大学青年人才孵化器(No.2014CY012)资助.

[1+1] and [2+1] Additions on a (5,5) Single-Walled Carbon Nanotube with V1~V4 Vacancies Based on Defect Curvature: A First Principles Study

Li Leia, Jia Guixiaoa,b, Wang Xiaoxiaa, Wu Tongweia, Song Xiwena,b, An Shenglia,b   

  1. a School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010;
    b Key Laboratory of New Functional Ceramics and Devices of Inner Mongolia Autonomous Region, Baotou 014010
  • Received:2016-11-29 Revised:2017-02-13 Online:2017-03-15 Published:2017-02-13
  • Supported by:

    Project supported by the Natural Science Foundation of Inner Mongolia (No. 2016MS0513) and Youth Talent Incubator of Inner Mongolia University of Science and Technology (No. 2014CY012).

本工作使用GGA-PBE方法研究了H和O在含有V1~V4空位(5,5)单壁碳纳米管[1+1](H/[1+1])和[2+1](O/[2+1])加成反应的结合能、几何和电子结构.基于方向曲率理论提出的缺陷曲率包括原子曲率(KM-def)和键曲率(KD-def)预测了空位缺陷区不同原子和键的加成反应活性.计算结果表明,不管是[1+1]还是[2+1]加成,V1和V3空位缺陷中含有悬空键的C原子化学活性最强,且在[2+1]加成反应中C与O原子形成了羰基;对空位缺陷区其它原子或键,H与(5,5)管V1~V4空位缺陷区的原子结合能随KM-def的增大而增大;O加成在大KD-def的C-C键时,C-C键易被打断,形成C-O-C产物结构,且相应的结合能较大;O加成在小KD-def的C-C键时,C-C键未被打断,形成三元环产物结构.H/[1+1]和O/[2+1]加成反应结合能除了主要受曲率的影响,还受到参与反应的C原子在(5,5)管最高占据分子轨道的电荷密度以及分波态密度的影响.这些研究将为含有空位缺陷碳纳米管的表面修饰提供理论依据.

关键词: 碳纳米管, 空位, 缺陷曲率, 电子结构, 加成反应性

Binding energies, geometric and electronic structures for[1+1] (H/[1+1]) and[2+1] (O/[2+1]) additions of H and O atoms on a (5,5) single-walled carbon nanotube with V1~V4 vacancies are studied using a GGA-PBE method in this work. Defect curvature proposed on the basis of directional curvature theory, including atomic curvature (KM-def) and bond curvature (KD-def), is used to predict the reactivities of different atoms and bonds at the defect structural area. We find that the existence of vacancy defects enhances the H and O adsorption ability on the (5,5) tube. The calculated results show that in the V1 and V3 defects the C atoms with two-coordination have the strongest chemical activity for[1+1] and[2+1] additions, and among which the C atoms participated into[2+1] additions form carbonyl groups with O. For other atoms and bonds at the defect structural area, the binding energies of one H atom on the (5,5) tube monotonously increases with the increase of KM-def. When the KD-def of C-C bonds for the O/[2+1] additions are large, the C-C bonds are easily broken, and they are corresponding to adducts with the C-O-C configuration structures and large binding energies. When the KD-def of C-C bonds are small, the C-C bonds are not broken, and they are corresponding to adducts with the closed-3MR (three-member ring) structures. The binding energies for the H/[1+1] and O/[2+1] additions on the (5,5) tube mainly are determined by the curvature and affected by the electronic density in frontier orbital and partial density of state (PDOS) of C atoms participated in the reactions. The large electronic density in the highest occupied molecular orbital (HOMO) and large PDOS of C atoms near the Fermi level strengthen the adsorption of H and O atoms on the (5,5) tube. This study will provide a theoretical basis for surface modifications of carbon nanotubes with vacancy defects.

Key words: carbon nanotubes, vacancies, defect curvature, electronic structures, additions