Fabrication of the photocatalyst thin films of nano-structured potassium titanate by molten salt treatment and its photocatalytic activity

The thin films of potassium titanate photocatalyst were fabricated by molten salt treatment and oxidation in air, using TiO2 thin films formed on Al2O3 balls as the substrate. The thin films were characterized by SEM, EDS, and XRD. The photocatalytic activity was evaluated by measuring the degradation rate of a methylene blue (MB) solution. The formation of nano-structured potassium titanate in the molten salt mixture and the influence on photocatalytic activity are discussed. The results show that the molten salt treatment was simple and useful to fabricate the thin films of nano-structured potassium titanate. The nano-lamellar potassium titanate with amorphous was formed, which is closely related to the carbonate ion in the molten salt mixture. 6-potassium titanate with nano-needle crystals was formed by crystallizing the potassium titanate during oxidation in air. The potassium titanate with the nano-lamellar had high adsorptivity, whereas 6-potassium titanate with nano-needle crystals had high photocatalytic activity.