Preparation and Quantitative Characterization of Nitrogen-Functionalized Multiwalled Carbon Nanotubes

Nitrogen-doped multiwalled carbon nanotubes (MWCNTs) were produced by catalytic chemical vapor deposition. The surface and structural properties were investigated by transmission electron microscopy, nitrogen physisorption, thermogravimetry-differential scanning calorimetry, temperature-programmed oxidation (TPO) and X-ray photoelectron spectroscopy. The surface of the purified sample contained 4.2% nitrogen atoms and comprised pyridine, lactam, pyridine oxide, pyridone and pyrrol functional components. TPO results reveal the combustion kinetics of each nitrogen-containing functional group. The nitrogen atoms are incorporated within the graphitic structure to give a basic surface, which will play an important role in the investigation of catalysis and energy conversion. A convenient route to a closed cup-like carbon nanostructure, applicable to field emission devices is also reported.