Anatase nanocrystals with 103 and 112 facets by hydrothermal transformation of titanate nanotubes

Well-faceted anatase nanocrystals were prepared via phase transition of titanate nanotubes by hydrothermal treatment at high pH (>10). The three-dimensional morphology and facets of these anatase nanocrystals were investigated. When the pH value was increased to 11.5 or higher, novel nanocrystals with a tail-fin-like structure on one side were found in the product. The facets of the tail-fin-like nanocrystal were investigated by high resolution transmission electron microscopy with a tilt-rotate holder. Based on the morphologies, corresponding crystal orientations and the knowledge of crystallography, the facets of the tail-fin-like nanocrystal were determined to be 103, 101 and 112. The formation mechanism of these nanocrystals was also discussed.