One-dimensional titania nanostructures: Synthesis and applications in dye-sensitized solar cells

One-dimensional (1D) titania (TiO₂) in the form of nanorods, nanowires, nanobelts and nanotubes have attracted much attention due to their unique physical, chemical and optical properties enabling extraordinary performance in biomedicine, sensors, energy storage, solar cells and photocatalysis. In this review, we mainly focus on synthetic methods for 1D TiO₂ nanostructures and the applications of 1D TiO₂ nanostructures in dye-sensitized solar cells (DSCs). Traditional nanoparticle-based DSCs have numerous grain boundaries and surface defects, which increase the charge recombination from photoanode to electrolyte. 1D TiO₂ nanostructures can provide direct and rapid electron transport to the electron collecting electrode, indicating a promising choice for DSCs. We divide the applications of 1D TiO₂ nanostructures in DSCs into four parts, that is, 1D TiO₂ nanostructures only, 1D TiO₂ nanostructure/nanoparticle composites, branched 1D TiO₂ nanostructures, and 1D TiO₂ nanostructures combined with other materials. This work will provide guidance for preparing 1D TiO₂ nanostructures, and using them as photoanodes in efficient DSCs.