Power generation by microbial fuel cells from sunlight

Photosynthetic processes may be harnessed in a microbial fuel cell to continuously re-generate the anode and cathode reactants from their products. Here we report our latest results in which the cathode half-cell of a sediment microbial fuel cell was enriched with photosynthetic organisms resulting in enhanced catalytic activity at the cathode surface. Slow scan voltammetry revealed the development of a catalytic cathode biofilm over time resulting in 100-fold greater power density compared to an identical cell unexposed to light. Catalytic activity at the cathode surface could be linked to a diel light cycle (12 h light:12 h dark), that also contributed to a flux of O₂, CO₂, and nitrogen in the cathode compartment; as well as sustained power during darkness. Here we report our findings from our initial phylogenetic analysis of the cathode community and its potential relationship to the cathode catalytic activity.