Surface, structural and optical investigation on Poly Vinyl Alcohol (PVA)/Bi2WO6 nanocomposite films

Bismuth tungstate (Bi2WO6) emerged as one of the most capable chromogenic compounds among transition metal oxide having wide opto-electronic applications. It is an n-type semiconducting material having bandgap around similar to 2.7eV. Conversely, Nano Composite (NC) materials have been investigated in order to tailor the properties polymers and also to widen the applications. In this context Poly (vinyl alcohol)/ Bismuth tungstate (PVA/Bi2WO6) NC films were prepared with various weight ratio of Bi2WO6 content viz.0, 0.1, 0.2 0.4, and 0.8 wt%. The solution combustion method was employed to prepare Bi2WO6 nanoparticles (NPs). Subsequently, synergistic effect of polymer matrix and Bi2WO6 NPs is characterized and analysed to estimate the enhanced properties. The surface morphology of the NC's films was explored by Scanning Electron Microscopy (SEM). Elemental analysis is carried out using EDAX. The formation of polymer NC and its microstructural properties were investigated by X-ray diffraction technique and it is revealed that there is formation of orthorhombic phase for Bi2WO6 NPs with an average size of 35nm. Interaction of NP and PVA is studied using FT-IR spectrometer. The optical constants were evaluated by UV-visible spectrometer and it was found that NC films bandgap energy varied from 5.4 eV to 2.85eV for direct and from 4.57eV to 2.38eV for indirect bandgap. It is anticipated that these unique organic-inorganic NC materials are the emerging functional materials in the field of opto-electronics.