Byl Oleg, Liu Jie, Yates John T
Department of Chemistry, Surface Science Center, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Langmuir. 2005 Apr 26;21(9):4200-4. doi: 10.1021/la040132w.
The oxidative etching of single walled carbon nanotubes (SWNTs) is useful for opening the end caps and the sidewalls of the nanotubes to provide access to the interior. We have studied the effect of successive treatment of SWNTs by 95% pure O(3)(g), which is a powerful and convenient oxidizing agent. The surface area of the SWNTs was measured following exposure to O(3)(g) at 300 K and also following heating to 1073 K in a vacuum to decompose the oxidized groups on the nanotubes, a procedure called etching. This O(3)-induced etching process was observed by scanning electron microscopy and by transmission electron microscopy, and the kinetics of the process was studied gravimetrically. It was found that O(3) attack occurs preferentially on the outermost geometric surface of the conglomerate sample of the nanotubes as a result of the high efficiency of O(3) to react in a few collisions with the nanotube surface. Ozone-induced etching causes the loss of pores in the 20 A diameter range as observed by nitrogen adsorption at equilibrium by density functional theory analysis.
单壁碳纳米管（SWNTs）的氧化蚀刻对于打开纳米管的端帽和侧壁以进入其内部很有用。我们研究了用95%纯度的O₃(g)对SWNTs进行连续处理的效果，O₃(g)是一种强大且方便的氧化剂。在300 K下暴露于O₃(g)后以及在真空中加热到1073 K以分解纳米管上的氧化基团（此过程称为蚀刻）之后，测量了SWNTs的表面积。通过扫描电子显微镜和透射电子显微镜观察了这种O₃诱导的蚀刻过程，并通过重量分析法研究了该过程的动力学。结果发现，由于O₃在与纳米管表面的几次碰撞中就具有很高的反应效率，所以O₃优先攻击纳米管团聚样品的最外层几何表面。通过密度泛函理论分析在平衡状态下进行氮吸附观察到，臭氧诱导的蚀刻会导致直径在二十埃范围内的孔隙损失。
