Surface Dielectric Barrier Discharge Plasma Modification of Waste-Derived Carbon Electrodes for Application in Microbial Fuel Cells

Abstract

Biomass-derived activated carbon has emerged as a promising electrode material for microbial fuel cells (MFCs), yet conventional chemical modification methods raise concerns over toxicity, waste management, and environmental safety. Plasma-based surface engineering offers a cleaner alternative, but traditional systems requiring vacuum chambers, controlled gas atmospheres, and high-frequency power sources limit large-scale implementation. Here, an atmospheric-pressure surface dielectric barrier discharge (SDBD) plasma process is developed to enhance palm kernel shell–derived activated carbon (PKS-AC) for MFC anodes, providing a cost-effective and sustainable route for electrode modification. XRD analysis confirmed the retention of amorphous carbon features, with broad (002) and (100) peaks preserved after treatment. SEM revealed progressive pore opening maximized at 3 kV, while EDX indicated a marked reduction in oxygen content from 12.06% to 6.46% and a corresponding carbon enrichment from 87.94% to 90.94%. Over-etching at 4 kV produced nearly pure carbon (99.20%) with negligible oxygen. MFC operation over 14 days showed that the 3 kV-treated electrode achieved a peak voltage of approximately 0.615 V, six times higher than untreated carbon. These preliminary results demonstrate the potential of SDBD plasma modification for sustainable waste-derived carbon electrodes, supporting further investigation toward long-term renewable energy applications.