Electrospinning of Cu Doped TiO₂ Nanofibers and their Potential Application in Photoanode of Dye-Sensitized Solar Cells

Abstract

Titania (TiO2) is an important material having found its use in many technological applications. Due to its large surface-to-volume ratio, TiO2 nanofibers (NFs) are drawing increased attention in 3rd generation photovoltaics. The electro-optical response of TiO2 can be tuned by metal doping and structural control at the nano level. In this research, NFs of copper (Cu) doped Titania (TiO2) were fabricated by using electrospinning. To do away with Polyvinylpyrrolidone (PVP), the NFs were calcined and annealed in air at 500°C for 2 hours. The Energy-Dispersive X-ray Spectroscopy (EDS) results confirmed the doping of copper inside the titania after calcination. Scanning Electron Microscopy (SEM) results show NFs of varying diameters mostly in the 80 nm to 200 nm regime. SEM of the post-annealed samples shows relatively rougher fibers of reduced size compared to the uncalcined samples. The increase in roughness and reduction in the NFs diameter means an increase in the overall surface area and more efficient charge transport as Hall effect measurement results depicted that after doping of copper in nanofibers, the conductivity improved by 2 times as compared to undoped nanofibers of titania. Moreover, Ultraviolet-visible Spectroscopy (UV-Vis) showed Cu doping shifted the absorption of the spectrum.