Eco-Friendly Production of Reduced Graphene Oxide from Spent Dry Cell Batteries for Bifunctional Bioelectricity Generation and Heavy Metal Removal in Microbial Fuel Cells

Abstract

In this study, the anode of a double-chamber micro-biofuel cellwas fabricated using reduced graphene oxide (rGO) derived from waste dry cell graphite electrode. This material was developed to enhance electron transfer while simultaneously removing lead (Pb 2+ ) ions from wastewater. The synthesized rGOwascharacterizedusing UV-Vis, SEM-EDS, XRD, FTIR, and Raman spectroscopy to investigate optical, morphological, and structural properties,molecular vibrational states, structural defects, and thermal stability of the materials. Electrochemical properties were evaluated using CV and EIS. During the 30-day MFC operation, the anodes produced using GO and rGOnanoparticleshad a remediation efficiencyof 82% and 85%, respectively. It also delivered a maximum power density of 72.4 mW/m 2 and a current density of 927 mA/m², both significantly higher than those of the GO electrode, 45.94 mW/m² and 856 mA/m², respectively. Lastly, the micro-biofuel cellmechanism and future recommendations are included.