Polyaniline mediated enhancement in band gap emission of Zinc Oxide

Abstract

Zinc Oxide (ZnO) nanoparticles are prepared using sol–gel technique; while Polyaniline (PANI) is prepared via chemical oxidative polymerization of aniline. For the formation of composites fixed weight of ZnO nanoparticles were physically blended, followed by grinding with increasing weight content of PANI. The mixture so obtained was compressed in the form of pellets for further studies. SEM micrographs showed changes in the morphology of ZnO nanoparticles from rods to flakes indicating the formation of composites. Raman studies reveal the presence of hydrogen linkages between ZnO and PANI. Photoluminescence (PL) shows a suppression of defect emission of ZnO nanoparticles and an enhancement in band gap emission. The presence of hydrogen linkages between ZnO and PANI leads to suppression of defects in ZnO nanoparticles and hence an enhancement in UV emission is observed. A large number of dangling bonds present on surface of nanorods are passivated by the hydrogen from polyaniline.