Developing environment-friendly and sustainable energy is urgent these days, as it can solve energy shortages and the pollution that come from fossil fuel. Therefore, Plant microbial fuel cells (PMFCs) start to get attention recently. PMFC is a novel technology that can convert chemical energy into electricity by using microbial in the rhizosphere of plants without producing harmful byproducts during the process. However, PMFCs suffer from some practical issues such as low power output and high costs of electrode materials. This gives rise to the progress of electrode material which can improve the power output and reduce the cost.

To break through the limits of PMFCs, the agricultural waste-derived carbons were prepared and optimized as the anode material in our self-designed Canna-indica PMFCs in this study. Green carbon materials utilizing agricultural waste as precursors are not only environment-friendly but also a part of circular economy which helps to mitigate bio-waste and improve society sustainability. The biowaste-derived activated carbon materials were characterized by Brunauer-Emmett-Teller (BET) surface area analyzer, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The high surface area, porosity morphology, and good conductivity of the biowaste-derived activated carbon are the promising characteristics of high-performance anode materials of PMFCs. The maximum power density of our self-made PMFC device can reach 61 mW m⁻². The average power density was maintained at 23 mW m⁻² during the long-term measurement. All of the results in this study demonstrate the potential of using agricultural waste as electrode material for improving the electricity production of PMFCs.