Observations of carbon nanotube oxidation in an aberration-corrected environmental transmission electron microscope.
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.
Stanford Nanocharacterization Laboratory, Stanford University, Stanford, California 94305, United States. alkoh@stanford.edu
Ai Leen
AL
Koh
Emily
E
Gidcumb
Otto
O
Zhou
Robert
R
Sinclair
D006358:Hot Temperature; D046529:Microscopy, Electron, Transmission / Q000379:methods; D036103:Nanotechnology; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010084:Oxidation-Reduction; D013499:Surface Properties; D014618:Vacuum
D037742:Nanotubes, Carbon