An Innovative Approach to Synthesize Highly-Ordered TiO₂ Nanotubes

An innovative route to prepare highly-ordered and dimensionally controlled TiO₂ nanotubes has been proposed using a mild sonication method. The nanotube arrays were prepared by the anodization of titanium in an electrolyte containing 3% NH₄F and 5% H₂O in glycerol. It is demonstrated that the TiO₂ nanostructures has two layers: the top layer is TiO₂ nanowire and underneath is well-ordered TiO₂ nanotubes. The top layer can easily fall off and form nanowires bundles by implementing a mild sonication after a short annealing time. We found that the dimensions of the TiO₂ nanotubes were only dependent on the anodizing condition. The proposed technique may be extended to fabricate reproducible well-ordered TiO₂ nanotubes with large area on other metals.