Metal-catalyst-free Growth and Characterization of Nitrogen-doped Carbon Nanotubes

Nitrogen-doped carbon(CNx) nanotbues were synthesized by detonation-assisted chemical vapor deposition with carbon nanotubes(CNTs) as catalysts and melamine as carbon/nitrogen sources.CNTs exhibit high catalytic activity for the metal-catalyst-free synthesis of CNx nanotubes.TEM,EDS,Mapping,XPS,Raman and TG were performed to characterize the synthesized CNx nanotubes.CNx nanotubes exhibit com-partmentalized bamboo-like structure,and contain high concentration of nitrogen(ca.17at%),which is ho-mogeneously distributed within compartment layers and tube walls.The pyridine-like and graphitic N are in-corporated into the graphitic network.The nitrogen doping induces the decrease of the graphitization degree and results in lower oxidation-resistance temperature.The synthesis of CNx nanotubes without metal catalysts will facilitate the applications of CNx nanotubes.