Phase transformation and thermal structure stability of titania nanotube films with different morphologies

Titania nanotube films composed of close-packed and loose-packed titania nanotube arrays were produced by electrochemical anodization of titanium. Phase transformation and thermal structure stability of the titania nanotube films with different morphologies were studied after they were annealed at different temperatures. Results show that the close-packed titania nanotube films started phase transformations from anatase to rutile at a relatively higher temperature, and exhibited higher thermal structure stability than the loose-packed titania nanotube films. The difference in the phase transformation and thermal structure stability of the close-packed and loose-packed titania nanotube films was analyzed from the viewpoints of specific surface area. The results in this paper provided understanding of the morphology effects on phase transformation and thermal structure stability of titania nanotube films.