Synthesis, Characterization, and Electrochemical Properties of Reduced Graphene Oxide Produced from Sugarcane Bagasse for Supercapacitor Applications

Reduced graphene oxide (RGO) stands out as a highly promising material with numerous potential applications. Various carbon sources can be used as starting materials for the production of RGO. This study explores the utilization of sugarcane bagasse (SB), a globally abundant agricultural waste material, as a precursor for RGO synthesis. Initially, SB underwent pyrolysis at 750°C at the rate of 10°C/min under flowing argon gas to extract the graphite phase. The Hummer’s method was then employed to convert the extracted graphite into graphene oxide (GO). The GO products were subjected to ultrasonication to break oxygen functional groups before reduction into RGO, using metallic zinc (Zn) as a reducing agent. The graphitic transformation at each synthesis step, from graphite to GO and, ultimately, to RGO, was confirmed through XRD and FTIR analyses. Additionally, the formation of RGO was further confirmed by Raman spectroscopy, which showed the characteristic D, G, and 2D bands of the RGO phase. SEM micrographs revealed the morphology of RGO as a flake-like 2D multilayer nanosheet with a sheet thickness of several hundred nm. This study also examines the effect of Zn powder concentration on GO reduction to form RGO. It was found that the appropriate amount of Zn was crucial for RGO synthesis, as an excessive amount led to the presence of Zn residue in RGO samples. These findings present a straightforward and effective approach to preparing RGO from sugarcane bagasse, which can be scaled up for industrial production. Furthermore, the investigation into the electrochemical properties of the RGO samples revealed excellent performance under optimized synthesis conditions, including a large surface area, high specific capacitance, conductivity, and good stability. This positions the RGO samples produced from SB as a promising electrode material for supercapacitor applications.