Designed Architecture of Multiscale Porous TiO₂ Nanofibers for Dye-Sensitized Solar Cells Photoanode

Multiscale porous (MSP) TiO₂ nanofibers (NFs) were fabricated using a simple electrospinning and etching process with TiO₂/SiO₂ composite NFs for high-efficiency dye-sensitized solar cells (DSSCs). TiO₂ NFs with different pore sizes (small, large, and multiscale) were prepared using SiO₂ nanoparticles of various sizes. The surface area of the MSP TiO₂ NFs was nine times higher than that of pristine TiO₂ NFs, providing sufficient dye adsorption for light harvesting as well as efficient paths for electrolyte contact. Moreover, the one-dimensional structure provides efficient light scattering and fast electron transport. As a result, DSSCs exhibited an enhanced current density (<i>J</i>_sc) of 16.3 mA cm^–2 and a high photoconversion efficiency (η) of 8.5%, greater than those of conventional photoelectrodes made of TiO₂ nanoparticles (<i>J</i>_sc of 12.0 mA cm^–2 and η of 6.0 %)