Transparent titania nanotubes of micrometer length prepared by anodization of titanium thin film deposited on ITO

► Anodization of RF sputtered Ti film on ITO glass. ► Electrolyte consisting of 0.75% (wt) NH4F and 2% (vol) H2O dissolved in ethylene glycol and anodization voltage of 40 V is optimal for TiO2 nanotube formation. ► Upper nanoporous layer are formed on top of top of well ordered and regular TiO2 nanotubes. ► Annealed nanotubes demonstrate lower transmittance than non annealed nanotubes in the visible region.