How Does the Choice of Anode Material Influence Electrical Performance? A Comparison of Two Microbial Fuel Cell Model Organisms

Abstract

Abstract The influence of the anode material on the electrical performance of the two microbial fuel cell model organisms Geobacter sulfurreducens and Shewanella oneidensis is investigated. High‐surface‐area activated carbon and low‐surface‐area graphite felt are compared in terms of polarization curves under quasi‐steady‐state conditions. Unexpectedly, G. sulfurreducens exhibits similar current densities up to 700 μA cm −2 independent of the anode material. This is ∼50 % higher than steady‐state values reported previously. The negligible influence of electrode material on the electrical performance of G. sulfurreducens is attributed to the fact that it performs only direct electron transfer, but forms thick biofilms. In contrast, S. oneidensis , relying mainly on mediated electron transfer, apparently makes better use of high‐surface‐area activated carbon and achieves higher current densities compared to graphite felt. This underlines the importance of tailoring anode materials according to the used organisms.

Key findings

• ▸Geobacter sulfurreducens exhibits similar current densities up to 700 μA cm⁻² independent of the anode material.
• ▸Shewanella oneidensis achieves higher current densities with high-surface-area activated carbon compared to graphite felt.
• ▸The difference in electron transfer mechanisms between the two microorganisms is attributed to the observed differences in anode material influence.

Keywords

Identifiers

DOI

10.1002/celc.201402036

Journal

ChemElectroChem

Year

2014