Chemical/structural characterization of carbon nanoparticles produced by laser pyrolysis and used for nanotube growth

Carbon nanoparticles produced by CO2 laser pyrolysis have been investigated using morphological and structural probes such as high-resolution scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and electron diffraction, as well as chemical probes, such as gas chromatography–mass spectrometry and fast atom bombardment–mass spectrometry. The produced particles resulted to have a spherical shape and a diameter of about 50 nm with graphitic domains of the order of 80 Å. They contain appreciable fractions of polycyclic aromatic hydrocarbons, which can be extracted with toluene, as well as fullerene units. The implications of these results for the use of carbon nanopowders in the carbon nanotube synthesis are also discussed.