Controlled synthesis of anatase TiO2 nano-octahedra and nanospheres: shape-dependent effects on the optical and electrochemical properties

TiO2 nano-octahedra and nanospheres were synthesized in toluene and ethanol solutions containing 2 mL of acetic acid and 60 mg of CTAB using a solvothermal method at 280 °C for 20 h. The crystalline phase of TiO2 samples was confirmed by X-ray diffraction and Raman spectroscopy. The morphology of TiO2 nanostructures was observed by scanning electron microscopy and transmission electron microscopy. The band gaps of TiO2 nano-octahedra and nanospheres were estimated from UV absorption spectra to be 3.18 and 3.23 eV. Further, due to shape-dependent properties, the TiO2 nano-octahedra show good storage performance with lithium ions when referenced to P25 TiO2.