Nano-structured carbon as electrode material in microbial fuel cells: A comprehensive review

The microbial fuel cell (MFC) is a very promising technology for generating electrical energy from anaerobic fermentation of organic and inorganic matter in wastewater using microorganisms as biocatalysts while simultaneously treating the wastewater. However, the overall low performance of the MFC compared to other more established fuel cell technologies and the high cost of its components compared to the low value of the wastewater it treated, are the two major barriers to commercialization. In recent years, MFC's performance has been improved by using among other things, cheaper nano-composite materials such as nano-structured carbon in the electrodes that are more conductive and mechanically stabile with larger surface area and higher electrochemical catalytic activity compared to the conventional Pt on carbon. However, the nano-structured carbon electrodes have also been reported to have some serious drawbacks such as toxicity to the microbial consortium in the biofilm attached on its surface, which reduces performance of the MFC. This paper tries to highlight the broad-spectrum of different nano-composite materials that have been used as electrode material in the MFC in recent years.