Controlled growth of TiO₂ nanorods capped with carboxylate groups by the solvothermal process

A solvothermal method is described for preparing nanomaterials of titanium dioxide (TiO₂) while controlling the growth of rod-shaped nanomaterials. Titanium (IV) isopropoxide (TTIP) and butyl ether were chosen as the precursor and solvent, respectively. Oleic acid and decanoic acid were used as the surfactant. TiO₂ nanospherical particles and nano-rods were synthesized in mass quantities by adjusting the kind of surfactant, the concentration of the precursor, and the solvothermal reaction temperature. The synthesized TiO₂ nanospherical particles and nanorods were uniform and transparent in the toluene. The TiO₂ nanospherical particles were about 3.5 nm in size. The TiO₂ nanospherical particles and nanorods were of a highly crystalline anatase structure. The direction of growth of the TiO₂ nanorods was [001] and the band gap energy of the TiO₂ nanorods, evaluated by optical absorption, was 3.34 eV.