Synthesis and characterization of graphene from waste dry cell battery for electronic applications

Abstract

This study demonstrates the electronic applications of graphene synthesized from the graphite electrode of waste dry cell zinc–carbon batteries. Graphite powder [G (R)] is successfully recovered from the graphite electrode of waste batteries by acid treatment and used as starting material for synthesis of graphene oxide (GO) following Hummers method. Finally, reduced graphene oxide (RGO) was obtained from the chemical reduction of GO by hydrazine hydrate. RGO thus obtained was characterized by X-ray diffraction, Raman spectroscopy, Fourier-transform infrared spectroscopy, UV-vis absorption spectroscopy, dynamic light scattering, energy dispersive X-ray spectra and transmission electron microscopy to get detailed information about the structure and morphology of the RGO. All the above characterization results confirmed the restoration of sp² conjugation and removal of functional groups after the reduction of GO and also the sheet like morphology of RGO. The surface charge and stability of RGO in an aqueous medium are examined by measuring zeta potential. An electrochemical study demonstrated that, at different sweep rates, the current is the highest for RGO and lowest for GO and the current increases with an increasing sweep rate for all materials. The loop area of all the samples at the 100 mV s⁻¹ sweep rate is the highest. The galvanostatic charging/discharging measurements have also been performed for both the GO and RGO samples at a current density of 1 mA g⁻¹. Electro-conductivity measurement shows that RGO has higher conductivity than GO due to the restoration of the sp² structure. The current voltage (I–V) characteristics show a non-linear behavior of GO and the ohmic nature of RGO.