Anodic Growth Behavior of TiO₂ Nanotube Arrays with Process Parameter Control

Figure 5

FE-SEM image of TiO₂ nanotube arrays with different concentration of NH₄F in electrolyte ((a) 0.3 wt%, (b) 0.5 wt%, and (c) 1.0 wt%) and their microstructure change (d).

(a)

(b)

(c)

(d)