Influence of temperature variations on the dielectric parameters of thermally reduced graphene oxide

Abstract

Large-scale production of graphene remains a great challenge in which the oxidation of graphite is a promising approach for it. Graphene has unique thermal, electrical, and mechanical properties, but it is in the most common solvents insoluble. Graphene oxide can be considered as an insulator or semiconductor material. As compared to the properties of graphene and graphene oxide (GO), the reduced graphene oxide (rGO) behaves as an intermediate state between graphene and GO. Graphene oxide has been successfully synthesized from graphite powder via Hummer’s method and followed by thermal treated at 800 °C for the reduction GO in order to obtain rGO. This work elucidates the preparation method of GO and rGO step-by-step in detail. Structural characterization by X-ray diffraction of the synthesized rGO explains that the preparation and reduction of GO were effective. The morphology and structure of GO and rGO were analyzed using Scanning Electron Microscopy (SEM). Fourier Transform Infrared (FTIR) analysis displayed the disappearing of some oxygen functional groups in rGO in comparison to GO, as well as some peaks of rGO were flattened due to the removal of the carbonyl group. The aim of this paper is to analyze the dielectric properties of rGO as a function of temperature. The pellet of rGO was prepared to study the dielectric properties with respect to temperature in the range of 25 °C–300 °C for selected frequencies using LCR meter. The relative dielectric constant (ε′), dielectric loss factor (ε′′), dielectric loss tangent (tanδ), and the impedance of rGO were found to depend highly on the extent of temperature.