Enhanced electron transfer in microbial fuel cells using calcined eggshell anode with optimized performance

This study investigates the impact of calcination temperature on eggshell-derived anodes for microbial fuel cells (MFCs), addressing the limitations of costly and inefficient electrode materials. Activated with NaOH, eggshells were calcined at 550, 700, and 850 degrees C, with 700 degrees C yielding the highest electron transfer rate constant (ks = 1.64 s_ 1) due to enhanced crystallinity and structural integrity. Electrochemical characterization confirmed the 700 degrees C calcined anode exhibited stable voltage output (185 mV) and maximum power density (70 mW m_ 2), outperforming other configurations. Compared to conventional carbon-based anodes, the optimized calcined eggshell anode provides improved electron transfer, biofilm formation, and cost-effectiveness. This work advances MFC technology by transforming waste into sustainable anodes, addressing prior limitations such as low electron transfer rates and high material costs. These findings highlight the potential of waste-derived materials for scalable, eco-friendly energy solutions.