Enhanced photocatalytic activity of potassium-doped titania photocatalyst films with nanosheet structure

Potassium-doped titania (K-doped TiO ₂ ) films had been prepared by molten-salt treatment in KNO ₃ for Ti-TiC coatings, containing different amount of TiC, in order to achieve enhanced activity of the films. When the amount of TiC is lower than 40%, the partial surface morphology of K-doped TiO ₂ films clearly shows a nanosheet structure, and the formed nanosheets could increase the accessible surface area. The results show that K-doped TiO ₂ with composite crystals has formed with different amount of TiC, and the relative Raman peak intensity of Ti-O-K bonding is highest for 40% TiC. Even avoiding high adsorption of K-doped TiO ₂ films, the films exhibit excellent and stable photocatalytic activity. With increasing the amount of TiC, the photocatalytic activity of K-doped TiO ₂ films first increases then decreases, reaching the highest for 40% TiC.