A novel process from cobalt nanowire to Co3O4 nanotube

Cobalt oxide (CO3O4) nanotubes were synthesized by calcining cobalt nanowires embedded in an anodic alumina template (AAT) in air. The morphologies and phases of the nanowires/nanotubes were studied by transmission electron microscope (TEM) and x-ray diffraction (XRD) respectively. A hypothesis of the tube formation process is presented and illustrated by experimental results. According to the experimental results, it is concluded that competition between the oxidation and the evaporation of cobalt nanocrystals plays a crucial role in the formation of such tube-like nanostructures Of CO3O4.