Photocatalysis of sculptured thin films of TiO2

Abstract

Enhanced surface reaction efficiency has been demonstrated in the photocatalysis of obliquely deposited ${\mathrm{TiO}}_{\mathrm{2}}$ thin films with variously shaped columns such as zigzag, cylinder, and helix. The columnar thickness and spacing play an important role in the enhancement of the effective surface area, while the columnar shape is less important. The optimum morphology for a surface reaction has been obtained at the deposition angle $\text{α=70°,}$ where the photocatalytic activity is 2.5 times larger than that at $\text{α=0°.}$ The morphology controlled obliquely deposited thin films are applicable for solar cell, electro- and photochromic devices besides photocatalyst.