Synthesis and photocatalytic activity of electrospun niobium oxide nanofibers

Niobium oxide (Nb2O5) nanofibers have been synthesized by sol–gel based electrospinning technique. Pure hexagonal phase (H-Nb2O5) and orthorhombic phase (O-Nb2O5) nanofibers were obtained by thermally annealing the electrospun Nb2O5/polyvinylpyrrolidone composite fibers in air at 500 °C and 700 °C, respectively. The fibers were characterized using the X-ray diffraction, scanning electron microscopy, specific surface area analyzer and UV–vis diffuse reflectance spectroscopy. Photocatalytic activities of the obtained nanofibers were evaluated depending on the degradation of methyl orange. The results indicate that the heat-treatment temperature, the crystalline structure and the morphology affected the physical and chemical properties of the as-prepared Nb2O5 nanofibers. The H-Nb2O5 nanofibers obtained at lower temperature showed better potential for the application as a promising photocatalyst.