Process of growth TiO2 nanotubes by anodization in an organic media

The aim of this chapter is to show the process for the growth of TiO2 nanotube by anodizing and its features as surface. The Ti anodized nanotubes were obtained by anodizing Ti in organic medium. The process of formation of TiO2 nanotubes on Ti surfaces was established ex-situ by Scanning Electron Microscopy (SEM). At first, the growth of the TiO2 on the surface of the Ti plate occurs because of the interaction of the Ti with O ions. Then, an early oxide layer is formed. These anions migrate through the oxide layer to the Ti/TiO2 interface and then react with Ti. Meanwhile, the applied electric field ejects Ti cations from the Ti/TiO2 interface and makes Ti move towards the TiO2/electrolyte interface. The chemical dissolution occurs at the interface of TiO2/electrolyte where TiO2 is dissolved by F with the help of H and the field assisted dissolution occurs at the Ti/TiO2 interface. Simultaneously, with the time of anodizing increased, the current density also increases to reach a maximum value. The increase in current density was caused by the formation of pits and enlargement of the pits on the oxide layer. Beyond this point, current density drops, indicating the growth of the nanotube structure. In this work, TiO2 nanotubes with inner diameter between 90-110 nm and wall sizes of 15-20 nm, after 120 min of anodizing are shown. The presence of TiO2 was confirmed with Energy Dispersive X-ray Spectroscopy (EDS) results. Tests of roughness, and surface energy were carried out too.