A Facial One-Pot Synthesis of Hierarchical TiO2 Nanourchins for Highly Efficient Dye-Sensitized Solar Cells

We report the facile one-pot hydrothermal synthesis of hierarchical TiO2 nanourchins (NUs) on an FTO substrate via controlled substrate directions and titanium precursors. The hierarchical TiO2 NUs, which composed of numerous spherical NUs of micrometer-sized dimensions of ∼8 μm formed on self-formation of a densely packed TiO2 nanowire (NW) layer were an ideal for dye-sensitized solar cells (DSCs) application due to a combination of large surface area, strong light scattering and direct electron transport network. The DSC based on hierarchical TiO2 NU photoanode grown using the mixed precursors of TiCl4 and Ti(OC4H9)4 had achieved an overall conversion efficiency of 2.68% which is 387.3% and 26.42% higher than that of DSCs based on pure TiO2 NW grown using TiCl4 precursor and TiO2 nanoparticles, respectively, because of the larger surface area and stronger light scattering.