Self-organized regular arrays of anodic TiO2 nanotubes.

The formation of self-organized regular arrays of oxide nanotubes lies in a delicate balance between the oxide growth rate and the oxide etching rate and a lattice mismatch between the grown metal oxide and the underlying valve metal. The requisites for their fabrication are the electropolishing and a two-step anodization. The most uniform and self-organized regular arrays of anodic TiO2 nanotubes among those known so far are reported as another example of valve metal oxide nanotube arrays since regular arrays of anodic aluminum oxide nanochannels were produced. Our findings can be generalized to fabricate self-organized regular arrays of other valve metal oxides.