The photocatalytic activity of an amorphous titanium oxide (a-TiOx) film was modified using a two-step deposition. The fluorinated base layer with a nano-textured surface prepared by a selective fluorination etching process acted as growth seeds in the subsequent a-TiOx deposition. A nanorod-like microstructure was achievable from the resulting a-TiOx film due to the self-assembled deposition. Compared to the a-TiOx film directly deposited onto the untreated base layer, the rate constant of this fluorinate-free a-TiOx film surface for decomposing methylene blue (MB) solution that was employed to assess the film's photocatalytic activity was markedly increased from 0.0076 min-1 to 0.0267 min-1 as a mechanism for the marked increase in the specific surface area.
Keywords: amorphous titanium oxide; nano-textured surface; photocatalytic activity; two-step deposition.