Facile synthesis and comparative study for the optical performance of different TiO2 phases doped PVA nanocomposite films

TiO2/PVA nanocomposites film was assembled using a solution casting technique, whereas the synthesis of TiO2 nanoparticles was achieved by the Sol-gel method. The control in TiO2 phases nanoparticle from Anatase, mix, and Rutile was taken place only by controlling the time and temperature of the calcination process, which belief as a new technique for that purpose. TiO2 nanoparticles with different phases employed as a filler and PVA as a host matrix. The established of TiO2 with different phases were examined by X-ray diffraction (XRD). At the same time, the shape and the approximate crystal size carried out by Transmission electron microscope (TEM), the XRD reveals the existence of anatase, rutile and mixed TiO2 phases with average crystallites size (D) of 7 nm 78 nm and 42 nm for anatase, rutile, and mix phases, respectively. TEM of TiO2 nanoparticles indicates the spherical shape of the rutile phase, and the tetragonal shape appears clearly in anatase, and the impact of the calcination process on crystal size was considerable. The grain size noted in the TEM image has a good agreement with the XRD results estimated by applying Scherrer's equation. The optical properties of TiO2/PVA composite films have been examined. The red-shifted of the direct optical band gap is achieved from 3.25 to 2.63 eV for phase transformation from anatase to rutile. The refractive index (n) dispersion was analyzed by applied the Wemple– Didomenico single oscillator model, and the dispersion parameters (Eo and Ed) were determined. Besides the photo-stability investigation of TiO2/PVA nanocomposite with the anatase phase of TiO2, which considers the characteristic phase.