Synthesis and characterization of sol–gel derived PVA-titanium dioxide (TiO2) nanocomposite

Novel PVA/TiO2 polymer nanocomposites have been prepared at low temperature via sol–gel route. XRD analysis showed the particles to be elongated along a- and b-direction but contracted along c-direction. PVA-assisted TiO2 nanocomposite samples dried at a temperature of 35 °C were found to have ~12 nm particle size. It was found that the composite nanoparticles had an increased degree of crystallinity in comparison to pure TiO2 dried at 80 °C. TEM analysis depicted the formation of highly dense nanorods (and prism)-like structure of increasing length and diameter depending on PVA concentration. Our studies revealed that by increasing the concentration of PVA in TiO2 the band gap was lowered from 3.55 to 1.65 eV. The photoluminescence studies showed that emission shifts towards higher wavelength (417–457 nm) accompanied by a reduction in impurity centres with increasing concentration of PVA in TiO2.