Diffusion of Metal in a Confined Nanospace of Carbon Nanotubes Induced by Air Oxidation

Air oxidation can result in the motion of metal confined in carbon nanotubes (CNTs). This can also be utilized to tailor various hybrid nanostructures. By controllable air-oxidation, as-prepared metal@CNT nanorods (a) can be converted first to core-shell-void nanorods (b), then to metal/metal oxide@CNT nanotubes (c), and finally to mesoporous metal oxide nanotubes (d). The metal/metal oxide@CNT nanotubes and mesoporous metal oxide nanotubes are expected to find many applications, such as in lithium ion batteries, catalysis, magnetic drug delivery, and gas sensing.