Mass-synthesized anatase titania nanocrystals with tunable size and shape via sol–gel in organic solvents with adsorbing ligands

High-quality anatase titania (TiO2) nanoparticles, nanowires, and nanorods have been mass-synthesized by the modified sol–gel method in the saturated fatty alcohol, acid, and amine systems with adsorbing ligands, respectively. These obtained quasi-spherical TiO2 nanoparticles showed the mean size of 16.5 nm with a narrow size-distribution. These resulting TiO2 nanowires had the uniform diameter of 3.8 nm with the length range of 80–180 nm, and TiO2 nanorods had the uniform diameter of 7.5 nm with the length range of 40–70 nm, respectively. We demonstrated that the shapes, sizes and morphology of these anatase TiO2 nanocrystals could be controlled systematically by adjusting certain reaction parameters, such as the kind of organic solvents, the alkyl length of organic solvents, and the reaction time. It has been found that the shape of the products was primarily determined by the kind of organic solvents. However, their sizes, size-distributions, and morphology could be controlled by adjusting the alkyl length of organic solvents and the reaction time. Based on the analysis of all experiment results, we have investigated the growth mechanism of these TiO2 nanocrystals with the different shape. Meanwhile, this synthetic method can be extended further for the preparation of other oxides nanocrystals.