Photosynthetic microbial fuel cells with positive light response

Abstract

Abstract The current study introduces an aerobic single‐chamber photosynthetic microbial fuel cell (PMFC). Evaluation of PMFC performance using naturally growing fresh‐water photosynthetic biofilm revealed a weak positive light response, that is, an increase in cell voltage upon illumination. When the PMFC anodes were coated with electrically conductive polymers, the rate of voltage increased and the amplitude of the light response improved significantly. The rapid immediate positive response to light was consistent with a mechanism postulating that the photosynthetic electron‐transfer chain is the source of the electrons harvested on the anode surface. This mechanism is fundamentally different from the one exploited in previously designed anaerobic microbial fuel cells (MFCs), sediment MFCs, or anaerobic PMFCs, where the electrons are derived from the respiratory electron‐transfer chain. The power densities produced in PMFCs were substantially lower than those that are currently reported for conventional MFC (0.95 mW/m 2 for polyaniline‐coated and 1.3 mW/m 2 for polypyrrole‐coated anodes). However, the PMFC did not depend on an organic substrate as an energy source and was powered only by light energy. Its operation was CO 2 ‐neutral and did not require buffers or exogenous electron transfer shuttles. Biotechnol. Bioeng. 2009; 104: 939–946. © 2009 Wiley Periodicals, Inc.

Key findings

• ▸PMFCs with conductive polymer-coated anodes showed a rapid and significant increase in voltage upon illumination.
• ▸The power densities produced in PMFCs were lower than those in conventional MFCs.
• ▸The mechanism of electron transfer in PMFCs is fundamentally different from that in anaerobic MFCs and PMFCs.

Keywords

Identifiers

DOI

10.1002/bit.22466

Journal

Biotechnology and Bioengineering

Year

2009