Anode modification: An approach to improve power generation in microbial fuel cells (MFCs)

Abstract

Global energy demand is continuously increasing and has become a matter of concern. At present, 86% of the energy demand are accomplished by fossil fuels, but these deliver harmful effects on the environment by releasing CO2 in the atmosphere. Contrary, though nonrenewable resources such as solar, wind, and bioenergy possess minimal carbon footprints, they suffer from limitations of higher installation cost, low efficiency, and complex operation system. Since the past two decades, a relatively new sustainable technology, the microbial fuel cells (MFCs) have emerged with potential to convert the bond energy of molecules present in organic/inorganic waste into electric energy with the help of microbes. The electricity produced through the release of electrons during microbial degradation of organic waste can be used to offset the running cost of wastewater treatment plants. The performance of the MFCs is influenced by a number of cofactors, viz. type of reactor, nature of feed, microbial consortia, electrode material, and mode of operation. Anode plays a significant role in the power enhancement. Across the globe, various research groups are working to enhance the efficiency and power output of anode through its modification using conductive polymers (polypyrrole and polyaniline), metal oxides, nanomaterials, and many others. MFC operated with the electrochemically reduced graphene oxide modified anode evidenced a power density enhanced by 17.5 times as compared to carbon cloth. In the past 5 years, power density ranging from 6.12 to 6119mWm?2 was observed with various modified anode. The chapter will throw light on anode materials popularly used in MFC, method/techniques used for its modification to enhance energy output and limitations that restrict its wide-scale application. � 2023 Elsevier Inc. All rights reserved.