Low-temperature green synthesis of few-layered graphene sheets from pomegranate peels for supercapacitor applications

Abstract

Graphene presents practical applications in energy storage devices, especially supercapacitors. However, mainstream synthesis of graphene includes toxic chemical usage, which threatens the environment. With the recent attention shift to synthesizing nanomaterials from agro-waste due to their easy availability, cost-effectiveness, and, most importantly, their environmental friendliness, we present, in this work for the first time, a novel and green synthesis of few-layered graphene sheets using pomegranate peels as a precursor at a low temperature of 80 °C. The surface morphology and microstructural properties are determined by Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray spectroscopy (EDX), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), UV–visible spectroscopy (UV–vis), and the electrical properties determined by Hall Effect Measurement. The application as a supercapacitor is also examined using Cyclic Voltammetry (CV), Charge–Discharge Cycling (GCD), and Electrochemical Impedance Spectroscopy (EIS). The resulting supercapacitor delivers an areal capacitance of 3.39 mFcm- 2 at a current density of 15.6 μA cm- 2 , making our synthesized graphene a good choice for electrochemical storage devices.