The effect of thermal treatment on the properties of TiO2 photocatalyst

Two new types of TiO2 photocatalysts were synthesised by precipitation from titanylsulphate solution by urea and compared with the commercial photocatalyst TiO2 P25 (Degussa). The photocatalysts were thermally treated at 300, 600 and 900 °C and characterised by X-ray diffraction, specific surface area and pore distribution analyses, and scanning electron microscopy. New photocatalysts exhibit a rather large surface area (300 m3 g−1) and small particle size (3–4 nm), and consist of round agglomerates (1–2 μm). Their photoactivity (degradation of oxalic acid and 4-chlorophenol) reached only about 60% of that of TiO2 P25 although they had a six times higher specific surface area. The possible reason could be a more efficient charge recombination in smaller TiO2 particles.