物理化学学报 >> 2012, Vol. 28 >> Issue (08): 1843-1848.doi: 10.3866/PKU.WHXB201205291

理论与计算化学 上一篇    下一篇

由锐钛矿(101)片卷曲成单壁纳米管的紧束缚密度泛函理论研究

刘昊, 林梦海, 谭凯   

  1. 厦门大学化学化工学院, 固体表面化学国家重点实验室, 福建省理论与计算化学重点实验室, 福建 厦门 361005
  • 收稿日期:2012-03-13 修回日期:2012-05-29 发布日期:2012-07-10
  • 通讯作者: 谭凯 E-mail:ktan@xmu.edu.cn
  • 基金资助:

    国家自然科学基金(20873107)和国家重点基础研究发展规划项目(973) (2011CB808504)资助

A Tight-Binding Density Functional Theory Study on Single-Walled Nanotubes from Anatase TiO2 (101) Sheets

LIU Hao, LIN Meng-Hai, TAN Kai   

  1. State Key Laboratory of Physical Chemistry of Solid Surfaces & Fujian Provincial Key Labo-ratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical En-gineering, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
  • Received:2012-03-13 Revised:2012-05-29 Published:2012-07-10
  • Contact: TAN Kai E-mail:ktan@xmu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20873107) and National Key Basic Re-search Program of China (973 (2011CB808504).

摘要:

通过卷曲二维锐钛矿(101)周期性单层片(sheets)构造了一系列不同手性((n,0), (0,m), (n,m))的一维单壁TiO2纳米管. 用周期性紧束缚密度泛函理论(DFTB)方法计算并比较了不同管径和手性的TiO2纳米管在几何结构、电子性质等方面的差别. 结果表明: 除了(6,0)管, 其余纳米管随着管径的增大, 应变能和能隙减小. 而在管径相同的情况下, 不同手性的(n,m)纳米管的应变能随着n/m的增加呈现先增大后减小的趋势, 能隙变化不大.

关键词: 紧束缚密度泛函方法, 二氧化钛, 锐钛矿, 纳米管

Abstract:

A series of chiral anatase (101) nanotubes (NT), which we refer to as (n,0), (0,m), and (n,m), can be formed by rolling up two-dimensional periodic anatase TiO2 (101) single layer sheets. Optimized parameters of the atomic and electronic structures of these nanotubes have been calculated using a tight-binding density functional theory method (DFTB). Their band gaps (Eg) and strain energies (Es) have been analyzed as functions of NT diameter. Except for (6,0), the strain energy and the band gap of all the nanotubes of various chirality decrease as the diameter increases. We also find that the strain energy increases first and then decreases rather than varying monotonically with almost constant band gap when n/m ranges from zero to infinitely large.

Key words: Tight-binding density functional method, TiO2, Anatase, Nanotube

MSC2000: 

  • O641