One-step hydrothermal fabrication of three dimensional anatase hierarchical hyacinth-like TiO2 arrays for dye-sensitized solar cells

We have demonstrated a facile synthetic strategy for the direct growth of branched, three dimensional anatase hierarchical hyacinth-like TiO2 (AHHT) arrays on fluorine-doped tin oxide glass substrate via a one-step hydrothermal method. The AHHT arrays with high specific surface area of 79.5 m2 g−1 are 400–650 nm in diameter and about 11 μm in length prepared at 200 °C for 12 h using potassium titanium oxalate, diethylene glycol, sodium chloride, and water. The AHHT arrays are constructed by a large number of nanosheets which are composed of nanowires, as confirmed by field emission scanning electron microscope and transmission electron microscope. A possible formation process of the AHHT arrays has been investigated by means of time-dependent experiment. Dye-sensitized solar cell based on the AHHT arrays exhibits an efficiency of 6.13% because of the synergistic effects of superior electron transfer, higher surface area and efficient light scattering.