TiO2 nanotubes, nanochannels and mesosponge: Self-organized formation and applications

Anodization of valve metals and alloys is a powerful tool to control nanoscale architecture for many metal oxides. Except for aluminum, the most explored system is self-organized oxide formed on titanium, namely self-organized TiO2 nanotubes, because of the unique combination of geometry with the semiconductive nature of titania that is applicable in photocatalysis, light harvesting systems, electrochromic devices, batteries, matrices, templates, filtration membranes, and bio-compatible materials. In this contribution, we review recent advances in the formation of nanostructured oxides in the form of nanotubes, nanopores with a through-hole morphology, mesosponges, nanochannels and microcones grown on Ti, Nb, Ta, Zr, Hf, W, V and their alloys. We discuss mechanisms of their formation, key functional features, and describe their applications in various fields of chemistry and electrochemistry. (c) 2013 Elsevier Ltd. All rights reserved.