A sustainable approach on utilization of waste-derived biochar in microbial fuel cell toward net-zero coalition

The growing need for sustainable energy solutions has led to the convergence of waste management and renewable energy technologies. This study delves into the application of waste-derived biochar in microbial fuel cells (MFC) to achieve a net-zero carbon footprint, contributing to the global sustainability agenda. Biochar, a carbon-rich product attained from the pyrolysis of organic waste materials, is examined for its dual role in waste management strategies and as an effective electrode material in MFC. The inherent characteristics of the biochar, including the porosity, surface area and conductivity, enhance the overall performance of MFCs, as well as the microbial activity such as nutrient retention and pH buffering, and promote efficient electron transfer. The current review emphasizes biochar's different sources, characteristics, and synthesis techniques. This review also discusses the application of biochar in MFC as anode and cathode, followed by its utilisation in soil amendment and bioelectricity generation. It also reviews the relationship between the economic analysis and the utilisation of biochar as electrode materials. Regardless of the synthesis techniques and biochar application, the limitations and future outlooks have also been discussed in detail.