Solvent-controlled synthesis of TiO2 1D nanostructures: Growth mechanism and characterization

One-dimensional (1D) anatase TiO2 nanostructures such as nanorods, nanowires and nanotubes with different aspect ratios were synthesized by a simple solvothermal process. The influence of the different organic solvents and the reaction time on the morphology, size and the formation of the nanostructures were investigated. The anatase TiO2 precursor powder reacted with highly alkaline aqueous solution, yielding layered sodium titanate nanosheets. These nanosheets transformed to different 1D sodium titanates nanostructures like nanorods, nanowires and nanotubes in the different solvents i.e. highly alkaline aqueous solution, highly alkaline water–ethanol and highly alkaline water–ethylene glycol mixed solvent, respectively. Acid treatment of these 1D sodium titanates resulted hydrated titanates and finally dehydration by calcinations at 500 °C in air gave the products retaining the morphology. The synthesized samples were characterized with XRD, SEM and TEM. All the 1D nanostructures showed intense and sharp absorption spectra indicated that the products were almost defect free. Photoluminescence studies of the nanostructures showed photostable UV emission properties that arise from the band-edge free excitation.