Large-scale fabrication of rutile TiO₂ with 3D hierarchical flower-like morphology

3D hierarchical flower-like rutile TiO₂ nanostructures (RTNs) were prepared via ion-exchange and calcination method from amorphous Ti-Na-O phase without using any surfactants or templates. The structure, morphologies and electrochemical behaviour of the as-prepared RTNs were investigated. The X-ray diffraction pattern (XRD) showed that the as-prepared sample was pure rutile TiO₂. The field emission scanning electron microscopy (FESEM) images revealed that the RTNs exhibited a flower-like shape, with nanopetals ca. 60 nm in width and 15 nm in thickness. The high-resolution transmission electron microscopy (HRTEM) demonstrated that the plane of the nanopetals was the rutile (110) plane. The as-obtained RTNs exhibited excellent rate capability (310 mAh g^-1 at a C/6 rate) during the initial cycle, which may be attributed to high electrode-electrolyte contact area offered by hierarchical nanostructures with large specific surface area.