Thermal chemical vapor deposition (T-CVD) growth of carbon nanotubes on different metallic underlayers

► Synthesis of carbon nanotubes on various substrates by thermal chemical vapor deposition. ► C2H2 is used as the carbon feedstock and the metallic underlayers such as AlCu, Cu, Ag, Ta, and NiV are used. ► A crucial component is insertion (or inclusion) of an Al layer between the metal and the catalyst. ► Types of CNTs could be dependent on the diameter of AlxOy nanoparticles. ► In situ mass spectrometry reveals that CO2 and H2O could be correlated to the formation of longer CNTs.