Inclusion of Crystalline Iron Oxide Nanoparticles in Uniform Carbon Nanotubes Prepared by a Template Carbonization Method

An attempt was made to encapsulate iron nanoparticles in uniform carbon nanotubes, which were prepared by using an anodic aluminum oxide film as a template. The pyrolytic carbon deposition from propylene was carried out on the uniform channels of the anodic oxide film, and then the MOCVD (metal-organic chemical vapor deposition) technique was applied to incorporate iron into the carbon-coated nanochannels. Ferrocene vapor was used as an iron precursor for the MOCVD under H₂ flow. The iron/carbon nanotube composites were liberated from the anodic oxide film by alkali treatment. It was found that the carbon nanotubes contain crystalline nanoparticles of Fe₃O₄ and their number and size are controllable by changing the MOCVD conditions. Furthermore, no iron oxide particles were found on the outer surface of the nanotubes.