Investigation of optical and electrical properties of graphene oxide/TiO2 nanocomposite

Abstract

We have successfully synthesized graphene oxide (GO), TiO2 nanoparticles and GO/TiO2 nanocomposite and studied their microstructural, optical and electrical properties through various analytical techniques such as XRD, FTIR, TEM, UV-visible spectrophotometer and LCR meter. The results of structural analysis reveal monophase of GO and TiO2 with formation of GO/TiO2 nanocomposite without any other impurity phase. TEM images clearly exhibit nanoparticles of TiO2, graphene sheets and distribution of the nanoparticles over the surface of graphene sheets. The variation in band gap is observed and found to decrease from 4.2 eV for TiO2 to 3.6 eV for the GO/TiO2 nanocomposite as estimated using Tauc's relation. Dielectric constant (ε') and dielectric loss (tanδ) are found to reduce with the increase in frequencies and results are explained on the basis of Maxwell-Wagner's two layer model.