Fabrication of 10 nm diameter TiO2 nanotube arrays by titanium anodization

We report the fabrication of TiO2 nanotube thin films using anodization method with HCl electrolyte and copper cathode. The process represents an alternative electrochemical approach using a non-noble metal cathode along with a safer electrolyte. In addition to the choice of electrolyte, the electrolyte concentration, anodization voltage, and anodization time all affect nanotube morphology. TiO2 nanotubes with diameters as small as 10 nm were achieved.