Improved photocatalytic degradation of textile dye using titanium dioxide nanotubes formed over titanium wires.

Titanium dioxide (TiO2) nanotubes formed by anodization over titanium wires show a significant improvement in photocatalytic activity compared to the nanotubes formed over foils. This is evident when the fractional conversion of a textile dye, methyl orange, increased from 19% over a foil to 40% over wires in the presence of nanotubes of identical dimensions illuminated over the same geometrical area. Higher degradation rates with Pt-TiO2 nanotubes over foils are matched by the Pt-free TiO2 nanotubes over the wires. The higher photocatalytic activity over the anodized wires can be attributed to the efficient capture of reflected and refracted light by the radially outward oriented TiO2 nanotubes formed over the circumference of the titanium wire. The formation of TiO2 nanotubes over wires can be considered as an effective alternate to improve photodegradation rates by avoiding expensive additives.