Indirect electron transfer in microbial fuel cells: Role of electron shuttles
The energy conversion can be realized using microbial fuel cells (MFCs) in which electrons extracted from organics are transferred to a solid electrode by electrogenic microorganisms. To make use of electrons donated by bacteria far away from the electrode, external electron transfer mediators were added to MFCs to enable the shuttles of electrons, causing a significant improvement of electron transfer efficiency and thus an increased power performance. Quinones and iron oxides are two types of electron shuttles that have been extensively studied in MFCs recently. Researchers have also employed different electrochemical approaches to explore the extracellular electron transfer mechanisms from cell to electrode mediated by these two electron shuttles. This presentation will mainly provide information about the different electron transfer mechanisms of quinones and iron oxides.