Low temperature synthesis of carbon nanotubes by thermal chemical vapor deposition using co-catalyst

Co-catalysts such as palladium (Pd), chromium (Cr) and platinum (Pt) are used for the decrease of the growth temperature of carbon nanotubes to 500-550 °C. Pd is found to be the most efficient co-catalyst for the reduction of the growth temperature of carbon nanotubes on Co-Ni catalytic metal particles deposited SiO₂ substrate by thermal chemical vapor deposition using C₂H₂. High-resolution transmission electron microscopy shows that the bamboo-shaped carbon nanotubes are grown at 500 °C using Pd, while the curled carbon nanofibers are grown at 550 °C using Cr.