Enhanced photocatalytic activity of titania coatings fabricated at relatively low oxidation temperature with sulfate-acid-bath pretreatment

Abstract

With the purpose of enhancing the photocatalytic activity of titania (TiO2) coatings with low cost, a method of sulfuric-acid-bath pretreatment followed by simple oxidation in air has been proposed to fabricate TiO2 coatings. The effect of oxidation temperature on the crystal structure, surface morphologies and photocatalytic activity of TiO2 coatings was investigated, to figure out the suitable oxidation temperature. XRD and Raman’s results show that the phase transformation of TiO2 starts at 773 K. The surface morphologies of TiO2 coatings clearly show the porous-like structure at lower than 873 K. With raising the temperature, the photocatalytic activity of TiO2 coatings firstly increases, then decreases, and reaches the highest at relatively low oxidation temperature of 773 K.