Synthesis and characterization of larger diameter carbon nanotubes from catalytic pyrolysis of polypropylene

Carbon nanotubes with larger diameter of about 160 nm have been synthesized through catalytic decomposition of polypropylene and maleated polypropylene using Ni as catalysts in autoclave at 700 °C. Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM) and high-resolution transmission electron microscope (HRTEM) images reveal the morphologies and structures of carbon nanotubes. The possible growth process of carbon nanotubes was also discussed. The results indicate that reaction temperature, maleated polypropylene and Ni catalysts play key roles in the synthesis of large diameters carbon nanotubes. Also, using waste polypropylene as starting material for preparing carbon nanotubes is feasible.