TiO2 Nanoparticles Synthesized with Ti(SO4)2 as Precursor via the Hydrothermal Method and their Optical Absorption Properties

Abstract

Anatase TiO2 particles of about 20 nm in the diameter were successfully synthesized with Ti (SO4)2 as titanium source and stronger ammonia water as precipitant at 240°C for 48 h with pH=5 using the hydrothermal method. The samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and ultraviolet-visible absorption spectroscopy (UV-VIS). XRD analysis showed that the phase of the samples was anatase TiO2. TEM analysis confirmed that TiO2 particles of about 50 nm in the diameter were obtained when the pH value was 0.12. With the increasement of the pH value, the size of as-prepared TiO2 particles became remarkably fine. However, with the further increase of the pH value, the size of TiO2 particles was not obvious. TiO2 particles of about 20 nm in the diameter were obtained when the pH value was 5. And UV-VIS results showed that the size of anatase TiO2 nanoparticles, which became small, was propitious to the blue shift of their absorption peak.