Titanium oxide nanowires originating from anodically grown nanotubes: The Bamboo-splitting model

An approach based on bamboo-splitting model to the synthesis of TiO 2 nanowires by the anodization of titanium foils in ethylene glycol (EG) containing NH4F ( EG + NH4F) solution, has been demonstrated. The anodization allows for the preparation of TiO2 nanotubes, which are vertically split off by electric-field-directed chemical etching, which leads to the formation of TiO2 nanowires on the entire nanotube arrays. A localized electrolysis of water on the TiO2 nanotubes was found to be crucial for the formation of the anodic oxide nanowires. It was also observed that small amount of acid in the EG + NH 4F solution causes a rapid dissolution of the formed oxide. annealing of the structure at 500 °C allowed for an amorphous-to-anatase transformation without a significant morphological change. This indicates that the method can be applied to obtain a large quantity of crystalline Ti 2 nanowires.