PVA assisted low temperature anatase to rutile phase transformation (ART) and properties of titania nanoparticles

Anatase to rutile phase transformation (ART) of titania nanoparticles is observed at very low temperature (180 degrees C) just by introducing polyvinyl alcohol (PVA) during co-precipitation followed by hydrothermal synthesis. The detailed investigations pertaining to the structural, optical and electrochemical properties of the nanosized titania and titania/PVA nanohybrid has been carried out. The crystallite size and crystal structure is confirmed using X-ray diffraction (XRD). Transmission electron microscopic (TEM) image reveals formation of spherical NPs in both the cases. Identification of functional groups is done using Fourier transform infrared spectroscopy (FTIR). The photoluminescence studies showed that emission slightly shifts towards higher wavelength side with remarkable decrease in intensity for TiO2/PVA nanocomposite (rutile samples). The remarkable decrease in PL intensity in TiO2/PVA nanocomposite (rutile samples) is explained considering the surface passivation during growth process. Ion transportation is monitored via Cyclic voltammetric (CV) and Electrochemical Impedance Spectroscopy (EIS) measurements. A significant enhancement of peak cathodic current in case of nanocomposite modified electrode is observed. It is assumed that TiO2/PVA (rutile) nanoparticles provided the conducting path for the electrons and hence enhanced the electrochemical reaction. (C) 2015 Elsevier B.V. All rights reserved.