Synthesis, structural and electrical properties of PVA/TiO2nanocomposite films with different TiO2phases prepared by sol-gel technique

Titanium oxide (TiO2) nanoparticles were fabricated by using the sol-gel technique. By controlling the calcination temperature, the different structures of TiO2(anatase and rutile) have been achieved which is considered a new technique for phase transformation. Moreover, PVA (polyvinyl alcohol)/TiO(2)nanocomposite with various TiO(2)phases was accomplished by room temperature casting method. The microstructure of TiO(2)nanoparticles and its effect on the PVA amorphous phase was confirmed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The functional groups of PVA and TiO(2)were inspected by Fourier transform infrared spectroscopy (FT-IR). SEM exhibits an agglomeration nature of TiO(2)nanoparticles through the PVA matrix. In this study, the dc conductivity, as well as the transport properties such as activation energy, ions number in unit volume, hopping distance, and polaron's radius were discussed. In the light-temperature of the polaronic hopping conduction models, the electrical conductivity data were examined which is well-described by polaronic models. Besides, it is noted that the nonadiabatic small polaron hopping conduction is realized in this system. The density of state and the decay constant values are acceptable for the localized states.