Facile synthesis of rice-like anatase TiO2 nanocrystals

Rice-like anatase TiO2 nanocrystals have been synthesized by hydrothermal treating Ti(OH)3 precursor in deionized water, which is easy to form in-situ a stable TiO2 aqueous dispersion and no post-synthetic purification process is required. The influences of synthetic parameters, such as reaction time and pH value, on the morphologies of the resulting nanocrystals have been investigated. It is found that the crystallinity and sizes of TiO2 nanocrystals increase with the reaction time increased. The pH value is important for controlling the sizes and shapes of TiO2 nanocrystals. As pH value increases from 2 to 11, spherical, rice-like, and rod-like TiO2 nanocrystals are obtained, respectively. The formation mechanism of rice-like anatase TiO2 nanocrystals is supposed to be a hydrothermal crystallization and Ostwald ripening process.