Stanford Nanocharacterization Laboratory, Stanford University, Stanford, California 94305, United States.
ACS Nano. 2013 Mar 26;7(3):2566-72. doi: 10.1021/nn305949h. Epub 2013 Feb 6.
We report the first direct study on the oxidation of carbon nanotubes at the resolution of an aberration-corrected environmental transmission electron microscope (ETEM), as we locate and identify changes in the same nanotubes as they undergo oxidation at increasing temperatures in situ in the ETEM. Contrary to earlier reports that CNT oxidation initiates at the end of the tube and proceeds along its length, our findings show that only the outside graphene layer is being removed and, on occasion, the interior inner wall is oxidized, presumably due to oxygen infiltrating into the hollow nanotube through an open end or breaks in the tube. We believe that this work provides the foundation for a greater scientific understanding of the mechanism underlying the nanotube oxidation process, as well as guidelines to manipulate the nanotubes' structure or prevent their oxidation.
我们报告了首例在具有像差校正功能的环境透射电子显微镜（ETEM）分辨率下对碳纳米管氧化的直接研究，因为我们在原位 ETEM 中定位和识别了随着温度升高而发生氧化的同纳米管的变化。与早期的报告相反，这些报告指出 CNT 氧化始于管的末端并沿其长度进行，我们的发现表明，只有外部的石墨烯层被去除，并且有时内部的内壁被氧化，这可能是由于氧气通过开口端或管中的裂缝渗透到空心纳米管中。我们相信这项工作为更好地理解纳米管氧化过程的机制提供了基础，同时也为操纵纳米管的结构或防止其氧化提供了指导。
