Study of bio-polymer derived graphene oxide-ZnO nano-composite thin films

Abstract

This study is focused on the growth of ZnO and graphene oxide nanocomposite thin films by a simple wet chemistry route. Here graphene oxide is derived from Shellac, a Bio-polymer. ZnO-GO thin films were deposited on glass substrates by an easy, cost effective drop casting technique using ZnCl2 and Shellac as the precursor materials. After deposition, the films were annealed at 600 °C for 1h in air. X-ray Diffraction was used to study the structure of the films which shows hexagonal structure of ZnO with reduced particle size in ZnO-GO composite films. Morphological study was done by Scanning Electron Microscopy which shows nanoparticles embedded in GO. Photoluminescence spectra indicate a shift in UV emission peak in near band edge emission due to interaction of GO with ZnO. Spectroscopic ellipsometry study shows a slightly reduced refractive index and larger extinction coefficient in ZnO-GO composite film in comparison to ZnO film indicating an increase in absorbance in ZnO-GO film paving the use of ZnO-GO films for photocatalytic application.