Carbon Nanotubes and Graphene - Research and Applications

Carbon nanotubes decorated by a high density of carbon nanoparticles of turbostratic stacked graphenes are fabricated by the hydrocarbon ion deposition with energy of 80 eV at 700 degrees C. The formation of carbon nanoparticles of turbostratic stacked graphenes is by virtue of the structure reconstruction driven by the high temperature annealing effect. There are two competing effects by the ion irradiation. One is the deposition effect of the carbon-based ions and the other is the etching effect by the hydrogen ions. At low hydrogen content in the gas phase, the deposition rate of carbon-based ions is faster than the etching rate by the hydrogen ions and CNTs are coated by carbon nanoparticles of turbostratic stacked graphenes. The nanoparticles extend from the nanotube surface and have a random distribution on the surface of CNTs at first. With the increasing duration of deposition, the whole surface of CNTs is coated by carbon nanoparticles of turbostratic stacked graphenes at last. Meanwhile, the size of nanoparticles decreases with the increasing hydrogen content. At intermediate hydrogen content, the etching effect is prominent and the structural quality of carbon nanoparticles of turbostratic stacked graphenes remains low, while amorphous structure begins to be introduced. At high hydrogen content, CNTs are exposed to the hydrogen ions and are etched into pieces of carbon particles, built from relatively steady sp3 bond carbon atoms.
Source: Carbon (2008), article in press