One step preparation of highly dispersed TiO2 nanoparticles

A facile approach was developed to prepare highly dispersed TiO2 nanoparticles with selected phase. The crystallization phase of the nanoparticles can be easily tuned from anatase to rutile by the dosage of hydrochloric acid in the reaction system. The crystallite size of the as-prepared anatase TiO2 nanoparticles was ca. 3.2 nm with high dispersion. A transparent TiO2 colloid was obtained by dispersing the as-prepared anatase TiO2 nanoparticles in deionized water without any organic additives added. The concentration of TiO2-H2O colloid can be as high as 1600 g/L. The optical transmittance of TiO2-H2O colloid with a low concentration was nearly 100% in the visible region. Furthermore, anatase TiO2 nanoparticles(TiO2-NPs) showed superior photocatalytic performance compared to rutile TiO2-NPs.