Electrochemical Characterization of Various Self-Assembled Nanocomposite Electrodes in E.coli-Catalyzed Mediatorless Microbial Fuel Cell

Microbial fuel cells (MFCs) is one of the promising green energy sources to produce electricity from organic wastes with the help of bacteria as catalyst. It converts the chemical energy in organic wastes into electricity by bioelectrochemical reactions. In spite of the promise of MFCs, their applications are limited by low power generation efficiency. Power limitations can be addressed by the use of better suited anodes, and to modify the electrode surface with nanostructures is one of the ways to improve the efficiency of the anode. In this study, We have demonstrated MFCs performance based on Escherichia coli (E.coli) by optimizing the electrode surface structure using various nanomaterials like reduced grapheme oxide(rGO), graphite nanofiber(GNF) and carbon nanotube(CNT). Each of the nanomaterials is doped with iron particles of 3~10nm size, and were formed into a nanocomposite. The synthesized nanocomposites was assembled on the anode electrode surface by directly applying a magnetic field. This conductive multilayer of nanocomposites coated on anode enhances the electron transfer between the bacteria and the anode. The electrochemical activities with each catalysts of such as Fe/rGO, Fe/GNF and Fe/CNT are investigated by cyclic voltammetry, Impedance spectra and polarization curve measurements.