物理化学学报 >> 2006, Vol. 22 >> Issue (04): 451-455.doi: 10.1016/S1872-1508(06)60016-8

研究论文 上一篇    下一篇

二氧化硅纳米管的稳定性及尺寸效应

徐灿;曹娟;朱莉芳;高晨阳   

  1. 兰州大学物理科学与技术学院, 兰州 730000; 兰州大学磁学与磁性材料教育部重点实验室, 兰州 730000
  • 收稿日期:2005-09-09 修回日期:2005-11-29 发布日期:2006-04-10
  • 通讯作者: 徐灿 E-mail:cxulzu@yahoo.com

Stability and Size Effect of Silica Nanotube

XU Can;CAO Juan;ZHU Li-Fang;GAO Chen-Yang   

  1. School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, P. R. China; Key Laboratory for Magnetism and Magnetic Materials of MOE, Lanzhou University, Lanzhou 730000, P. R. China
  • Received:2005-09-09 Revised:2005-11-29 Published:2006-04-10
  • Contact: XU, Can E-mail:cxulzu@yahoo.com

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摘要： 运用密度泛函计算, 对无水(SiO2-NTs)和水合(SiO2-WNTs)的SiO2纳米管进行结构优化和频率计算, 研究了与尺寸有关的平均结合能和红外光谱. SiO2-WNTs中发现当纳米管的层数或长度相同时平均结合能相等. SiO2-WNTs比SiO2-NTs和二元环直链结构都要稳定. 对截面为四元环的纳米管红外光谱的分析发现, 振动峰值与实验值相吻合, 且切向和径向振动显示较强的尺寸效应. SiO2-WNTs是一维SiO2纳米管一种合适的结构模型.

关键词: 纳米管, 尺寸效应, 红外振动, 稳定性

Abstract: The structure and infrared vibration of silica nanotubes with anhydrous structure(SiO2-NTs) and hydrogen-capped structure (SiO2-WNTs) have been investigated using the density-functional theory (DFT). It was found that the average binding energies were almost the same for SiO2-WNTs having same layer numbers or length. SiO2-WNTs are energetically more favorable than the SiO2-NTs and two-membered ring (2MR) molecular chains structure. IR spectrum of 4MR-WNTs was in well accord with the experimental data and the vibrations of oxygen atoms with directions parallel and normal to the axis of nanotubes show a strong size effect. The SiO2-WNTs would be considered as an appropriate structure model for one-dimensional silica nanotube.

Key words: Nanotube, Size effect, IR vibration, Stability