New Route Producing Large-Scale Graphene Nanosheets from Corn Waste for Electrochemical Material

In this study, a novel method for synthesizing carbon-containing graphene nanosheets (CCG) from corn cob (CC) waste was developed. The CCG was produced through a two-stage pyrolysis process at various temperatures (200 °C and 300 °C) and durations (0.5, 1, and 1.5 hours). This new method is expected to enhance the graphene quality and offer a cost-effective solution for graphene synthesis from waste materials. The structural characteristics of the CCG were confirmed by X-ray diffraction (XRD), which revealed peaks indicative of graphene, and Fourier transform infrared (FTIR) spectroscopy, which exhibited similarities to previously reported graphene spectra. The optimal CCG sample, synthesized at 300 °C for 0.5 hours followed by 1.5 hours, was characterized by a hexagonal honeycomb structure and achieved the highest carbon content at 87.65% (w/w), as determined by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The electrochemical properties of the CCG were evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV). Although the charge transfer resistance (Rct) of the CCG-modified glassy carbon electrode (GCE) was found to be higher (3.93 kΩ) compared to the bare GCE (0.30 kΩ), the suboptimal electrochemical performance may be attributed to the presence of impurities, particularly oxygen. Nonetheless, this research highlights the potential of CC waste as a sustainable precursor for the large-scale production of graphene, contributing to the development of eco-friendly materials.