Nitrogen-doped carbon nanotubes synthesized with carbon nanotubes as catalyst

Nitrogen-doped carbon (CN(x)) nanotubes were synthesized with carbon nanotubes (CNTs) as catalyst by detonation-assisted chemical vapor deposition. CN(x) nanotubes exhibited compartmentalized bamboo-like structure. Electron energy loss spectroscopy and elemental mapping studies indicated that the synthesized tubes contained high concentration of nitrogen (ca. 17.3 at.%). inhomogeneously distributed with an enrichment of nitrogen within the compartments. X-ray photoelectron spectroscopy analysis revealed the presence of pyridine-like N and graphitic N incorporated into the graphitic network. The catalytic activity of CNTs for CN(x) nanotube growth was ascribed to the nanocurvature and opening edges of CNT tips, which adsorbed C(n)/CN species and assembled them into CN(x) nanotubes. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.