Crystalline phase transformation of electrospinning TiO2 nanofibres carried out by high temperature annealing

In this work reports the crystalline phase transformation of electrospinning TiO2 nanofibres by annealing at high temperatures. The nanofibres chemical stoichiometry was determined by Energy-dispersive Xray spectroscopy (EDS), which allowed find that the TiO2 crystal phase transformation is caused by oxygen vacancy generation. The TiO2 nanofibres diameter varied from 137.0 to 115.3 nm in the temperature range of 100-1000 degrees C, which was estimated by Scanning Electron Microscopy. The TiO2 nanofibres structural transformation from pure anatase to pure rutile structures, including the quasiamorphous and anatase-rutile mixed phases has been confirmed by Raman scattering and X-ray diffraction. The Raman spectroscopy exhibits the anomalous behaviour for band broadening and shifting of Raman bands with increasing crystallite size that form the nanofibres. By X-ray diffraction was found that the nanofibres crystalline phases present as preferential growth direction (101) for anatase and (110) for rutile. (C) 2019 Elsevier B.V. All rights reserved.