Effect of bath type on the formation of TiO2 nanotubes in fluoride containing aqueous solution

TiO2 nanotubes were formed on Ti electrochemically by the application of anodic current in 1 M H3PO4 + 0.3 M HF solution in a glass and Teflon bath. The TiO2 nanotubes could be partly grown in the glass bath while a uniform growth of TiO2 nanotubes was observed over the whole surface in the Teflon bath. The TiO2 nanotubes fabricated in the glass bath broke off readily during ultrasonic cleaning in distilled water while the TiO2 nanotubes formed in the Teflon bath was not damaged by the ultrasonic cleaning up to 5 minutes. The ultrasonic cleaning could remove the surface residuals which are obtained inevitably if TiO2 nanotubes are fabricated in aqueous solutions.