Synthesis of long aligned iron-encapsuled multiwall carbon nanotube array

Multiwall carbon nanotubes (MWCNTs) encapsuled with iron nanowires were fabricated by chemical vapor deposition (CVD) methods in furnace using ferrocene and xylene as catalyzer and carbon source. The MWCNTs were characterized by scanning electron microscope, transmission electron microscopy, X-ray diffraction and Raman spectroscopy. The results indicate that the MWCNTs have good alignment and fine multilayer graphite form, and a small number of iron(Fe) catalyzer nanowires and nanoparticles remaining in the MWCNTs consist of Fe and Fe3C, which are the outcomes of continuous supply of carbon source and iron catalyst particles. According to the synthesis process and characterization results, the possible growth mechanism of the MWCNTs is believed to accord with the base-growth model, which follows the cyclic process of catalyst nucleation on the open ends of MWCNTs from active gas phase cluster and then diffusion and formation of particles along inner surface of MWCNTs.