Microstructural, optical and electrical transport properties of WO3 nanoparticles coated polypyrrole hybrid nanocomposites

Abstract

The polypyrrole films modified with different weight percentages of WO3 nanoparticles were fabricated on glass substrate by a drop casting method. X-ray diffraction analysis showed that the broad diffraction peak of PPy becomes sharper and more intense as the WO3 nanoparticles content in the polymer based composite increases this revealed that the hybrid composites are more crystalline than PPy. The shift in FTIR peaks of the hybrid nanocomposite compared with PPy confirms that hybrid nanocomposites are not a sample mixture but could enhance the properties of each other on a molecular level; there may be a synergic interaction between the PPy and WO3 nanoparticles. The FESEM, TEM, AFM images of the nanocomposites shows the uniform distribution of the WO3 nanoparticles in the PPy matrix. The chemical compositions and intermolecular interactions within the polymer nanocomposite were explored by EDX and XPS spectra. The Uv-vis study shows shift in absorption peaks of PPy-WO3 (50%) hybrid nanocomposites towards lower wavelength implies that there is strong interaction between PPy and WO3 nanoparticles. The DC electrical conductivity of pure PPy was observed to be dependent on percentage of WO3 nanoparticles loading i.e., conductivity of hybrid nanocomposite increases with increase in the percentage of WO3 nanoparticles. The increase in the DC conductivity of PPy-WO3 (10-50%) hybrid nanocomposites may be due to increase in electrons mobility to high extended chain conformation to increase tunneling probability in all succeeding composites and attributed the versatile semiconducting behavior of WO3. (C) 2014 Elsevier B.V. All rights reserved.