Low-temperature synthesis of phase-pure 0D-1D BaTiO₃ nanostructures using H₂Ti₃O₇ templates

One-dimensional (1D) barium titanate (BaTiO₃) nanowires, which were uniformly covered with 0D BaTiO₃ nanocrystals, were synthesized by using a simple solvothermal reaction of protonated trititanate (H ₂Ti₃O₇) nanowires with barium hydroxide octahydrate [Ba(OH)₂·8H₂O] at 80 ° C in ethanol/ water mixed solvent systems. The compositions of the mixed solvents - the volume ratio of ethanol to deionized water - was a key controlling parameter in order to determine the phase formation and primary particle size of the 0D BaTiO₃ nanocrystals. Single-phase cubic perovskite BaTiO₃ started to form at 80 ° C in a mixed solvent containing more than approximately 60% by volume of ethanol. Field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM) analysis revealed that the as-prepared BaTiO₃ retained its wire-shaped morphology with nanocrystals on the surface. Furthermore, the synthetic mechanism of the 0D-1D BaTiO₃ nanostructures was demonstrated in view of the dielectric tuning of the mixed solvent and the similarities between the crystal structures of BaTiO₃ and H ₂Ti₃O₇.