Influence of Anodic Oxidation Parameters of TiO₂ Nanotube Arrays on Morphology and Photocatalytic Performance

Figure 6

Schematic diagram of nanotube evolution at constant anodization voltage: (a) oxide layer formation, (b) pit formation on the oxide layer, (c) growth of the pit into scallop shaped pores, (d) the metallic region between the pores undergoing oxidation and field assisted dissolution, and (e) fully developed nanotubes with a corresponding top view.

(a)

(b)

(c)

(d)

(e)