Ligand-mediated shape control in the solvothermal synthesis of titanium dioxide nanospheres, nanorods and nanowires

Abstract

A versatile synthetic method, based on a solvothermal synthesis technique, has been developed for the fabrication of TiO₂ nanocrystals with different shapes, such as nanowires, nanorods and nanospheres. The central characteristic of our approach is the production of a coordination complex at an intermediate stage of the reaction that possesses appropriate symmetry using two distinct ligands, oleic acid and oleylamine. Those ligands have different binding strengths, which specifically dictate the shape of both the coordination complex and the resulting TiO₂ nanostructures. Additionally, this approach yields, for the first time, monodisperse, 4 nm anatase TiO₂ nanocrystals by controlling the symmetry of the intermediate and solvothermal conditions.