Influence of the Catalyst Hydrogen Pretreatment on the Growth of Vertically Aligned Nitrogen-Doped Carbon Nanotubes

Thin vertically aligned N-doped nanotubes with narrow layered nanotube diameter distribution and a defined doping level have been synthesized by chemical vapor deposition. Multilayered catalysts and a pure acetonitrile C/N feedstock have been employed. The observed nitrogen content was up to 6% with a predominant sp2 bonding configuration in relation to other nitrogen incorporated forms. Depending on the process parameters, we were able to tune the nitrogen content and the formation ratio of small nanotubes to bamboo nanotubes. The use of multilayer catalyst allows a large temperature window in which substitutionally doped structures form in comparison to other catalysts.