Energy Production from Cheese Whey Using Boron-Incorporated Graphene Oxide Catalyst in Plant Based Microbial Fuel Cells

Abstract

Plant microbial fuel cells (PMFCs) represent a promising technology for sustainable bioelectricity generation while enabling organic waste valorization. In this study, boron-modified graphene oxide (BGO) electrocatalysts were synthesized via electrochemical exfoliation of 8B pencil graphite, followed by ultrasonication-assisted boron incorporation at 5 °C and 55 °C. ICP-OES analysis confirmed boron contents of 200.7 ppm and 651.7 ppm for BGO-5 and BGO-55, respectively. Raman spectroscopy revealed an increased I_D/I_G ratio for BGO-55 (0.82) compared to GO (0.68), indicating enhanced structural disorder and defect density, which is hypothesized to be associated with boron-induced perturbations within the graphene oxide framework. Electrochemical characterization (CV and EIS) demonstrated improved oxygen reduction (ORR) activity and reduced charge-transfer resistance for BGO-55, supporting the role of defect-enriched, boron-modified structures in facilitating electron transfer. When integrated into soil-based single sugar beet PMFC systems, BGO-55 significantly enhanced power density in both anode (0.936 mW m⁻²) and cathode-modified (0.967 mW m⁻²) configurations following whey supplementation. The improved performance is attributed to the synergistic interaction between increased boron content, defect-mediated electronic modulation, and enhanced ORR kinetics under substrate-enriched conditions. These findings suggest that low-temperature sonochemical boron incorporation offers a scalable and energy-efficient strategy to improve PMFC performance while promoting sustainable energy generation and agro-industrial waste utilization.