Photoluminescence: A very sensitive tool to detect the presence of anatase in rutile phase electrospun TiO 2 nanofibers

Abstract This paper reports on the synthesis and the characterization of titanium dioxide (TiO2) nanofibers prepared by electrospinning. The samples were annealed at various temperatures in air for 4 h. The as-spun and annealed TiO2/PVP composite nanofibers were characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy analysis (EDX), X-ray diffraction (XRD), Raman spectroscopy and photoluminescence (PL). The results show that the heat treatment has an effect on the crystallization process. Even if the XRD data shows a complete anatase-to-rutile transition in the TiO2 nanofibers at 900 °C, photoluminescence reveals a small portion of anatase in rutile sample.…