Control synthesis of rutile TiO2 microspheres, nanoflowers, nanotrees and nanobelts via acid-hydrothermal method and their optical properties

Abstract

Semiconductor rutileTiO₂ nanostructures with a diversity of well-defined morphologies, such as microspheres, nanoflowers, nanotrees and nanobelts, are synthesized via an acid-hydrothermal process without any structure-directing agents. Their morphologies, crystal structures and orientation relationship were characterized by X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy. By controlling hydrochloric acid concentration, anisotropic growth of the rutile TiO₂ leads to various morphologies. The synthesis mechanism of rich TiO₂ nanostructures was also studied. Finally, the relationship between optical properties and the structural complexity of the rutileTiO₂ nanocrystals was characterized.