Boron-mediated nanotube morphologies.
Boron-mediated nanotube morphologies.
复制标题
硼介导的纳米管形态。
作者：
R. Nicholls;Z. Aslam;M. Sarahan;A. Koós;J. Yates;P. Nellist;N. Grobert
碳纳米管的杂原子掺杂是一种公认的控制其性能的方法。然而，多壁碳纳米管(MWCNTs)中杂原子浓度的变化往往会在同一样品中产生不同形貌的纳米管，从而产生不同的性质。电子能量损失谱结合扫描电子显微镜(STEM)成像是精确绘制碳纳米管中呈现不同结构的杂原子的空间变化和成键状态的有力工具，例如B、N、P、Si或这些原子的组合。透射电子显微镜分析表明，多壁碳纳米管生长过程中的B掺入(B-MWCNTs)形成了三种不同的纳米管形态。这些结构包括具有富含B的锥体核心和C外层的核-壳结构、含B的锥体结构以及具有不规则内通道的多壁碳纳米管。利用纳米工厂()支架实验进行了原位研究，以考察单个B-MWCNT的性质，并表明三种类型的纳米管经历了不同的电流诱导击穿。B-MWCNT的组成、结构和性能的不均匀可能是由于炉内化学成分和温度的变化造成的，这项工作强调了开发能够控制杂原子进入纳米管的合成技术的重要性。
The "doping" of carbon nanotubes with heteroatoms is an established method of controlling their properties. However, variations in heteroatom concentration in multiwalled carbon nanotubes (MWCNTs) tend to produce nanotubes with different morphologies, and hence varying properties, within the same sample. Electron energy loss spectroscopy in conjunction with imaging using a scanning transmission electron microscope (STEM) is a powerful tool to precisely map the spatial variation and bonding state of heteroatoms, e.g., B, N, P, Si, or combinations of these, present in carbon nanotubes exhibiting different structures. TEM analysis revealed that B incorporation during MWCNT growth (B-MWCNTs) results in nanotube morphologies that can be divided into three different types. These include core-shell structures possessing a B-rich core of cones and a C outer layer, B-containing cone structures, and MWCNTs with an irregular inner channel. In situ studies were carried out using Nanofactory() holder experiments in order to investigate the properties of individual B-MWCNTs and to show that the three types of nanotubes undergo different current-induced breakdown. The inhomogeneity in composition, structure, and properties of B-MWCNTs could result from the variation in chemical composition and temperature within the furnace, and this work highlights the importance of developing synthesis techniques that can control the inclusion of heteroatoms into nanotubes.
影响因子：
10.9
作者：
Koos, Antal A.;Nicholls, Rebecca J.;Grobert, Nicole
通讯作者：
Grobert, Nicole