The effect of substrate morphology on the diameter distribution of carbon nanotubes grown on silica and ceramic substrates

Large-scale well-aligned carbon nanotube film and carbon nanotube bundles have been fabricated on smooth silica and rough polycrystalline ceramic substrates by pyrolysis of ferrocene/melamine mixtures. The images of transmission electron microscopy (TEM) and scanning electron microscope (SEM) show that carbon nanotubes grown on the silica substrate have uniform outer diameters of about ∼ 25 nm and lengths of about 40 μm, while those on the ceramic substrate have outer diameters from 10 to 90 nm and lengths up to 100 μm. Electron energy-loss spectroscopy (EELS) spectra show that nanotubes grown on the two different substrates are pure carbon tubes. The effects of substrate micro-morphologies on the diameters of carbon nanotubes have been discussed.