Carbon nanotubes from catalytic pyrolysis of deoiled asphalt

High purity and uniform carbon nanotubes with about 35 nm in diameter were produced by pyrolysis of deoiled asphalt in the presence of ferrocene in an atmosphere of hydrogen and argon at 1000 °C. Characterization of carbon nanotubes was carried out by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectroscopy (EDS), Raman spectroscopy and X-ray diffraction (XRD). The carbon nanotubes were highly graphitized with amorphous carbons covering the outside wall. The influence of temperature on the preparation of carbon nanotubes was also discussed.