Waste-derived rGO-doped calcium carbonate nanocomposites: a green approach for enhanced electrochemical energy storage

Experimentally, the electrochemical behaviour of rGO-doped CaCO₃ nanocomposite was determined. Reduced graphene oxide (rGO) was synthesized using graphite rod from the waste pencil battery. The graphite rod was used for the synthesis of rGO nanoparticles and also aided in the management and recycling of waste materials. However, the nanocomposite was synthesized by adding rGO into the calcium carbonate (CaCO₃) matrix through a simple approach technique that is chemical-free, non-hazardous, simple, and rapid. The synthesized nanoparticles and nanocomposite were characterized using FESEM and FTIR. While the 5% rGO reinforced nanocomposite shows three distinct peaks around 1739 cm⁻¹, 1421 cm⁻¹, and 1216 cm⁻¹ confirmed by FTIR analysis. The electrochemical analysis was done using three-electrode methods. Notably, the 5% rGO-doped nanocomposite exhibited excellent electrochemical performance, delivering specific capacitances of 55, 39, 22, and 14 F/g at current densities of 2, 3, 4, and 5 A/g, respectively.