Photocatalytic Properties of Columnar Nanostructured TiO_𝟐 Films Fabricated by Sputtering Ti and Subsequent Annealing

Figure 4

Cross-sections and surface morphologies of columnar nanostructured TiO₂ films after annealed at 400°C for (a) 1 hour, (b) 2 hours, (c) 3 hours and (d) 4 hours.

(a)

(b)

(c)

(d)