High‐Aspect‐Ratio TiO 2 Nanotubes by Anodization of Titanium

Growing holes: With the aid of a new technique highly organized surface layers of TiO2 nanotubes that are open at one end (see picture) are formed by the anodization of titanium. The pore structure is determined by the pH gradient within the forming pore, this in turn is controlled by the electrochemical sweep rate and the electrolyte concentration.