Comparative study on photocatalytic properties of TiO2 nanoparticles prepared in acidic medium and basic medium by hydrothermal method

In order to investigate the difference of phtotocatalytic properties of TiO2 samples prepared in different pH conditions, TiO2 nanoparticles were prepared in acidic medium and basic medium by a hydrothermal process, respectively. The samples were characterized using XRD, TEM, BET, XPS, surface photovoltage spectroscopy (SPS) and field-induced surface photovoltage spectroscopy (FISPS). Effects of temperature and pH in the hydrothermal process on particle sizes, specific surface areas, and photocatalytic properties of the TiO2 nanocrystalline were investigated. The experimental results indicate that the photocatalysis activity of TiO2 nanoparticles prepared in basic medium (B-TiO2) is superior to that in acidic medium (A-TiO2), which is ascribed to the difference of surface state between A-TiO2 and B-TiO2.