Porous ceramic anode materials for photo-microbial fuel cells

Abstract

This study focuses on porous ceramics as a promising new type of anode material for photo-microbial fuel cells (p-MFCs). The anodes were made from titanium dioxide and chemical vapour deposition was used to coat them with a layer of fluorine doped tin oxide (FTO) to make them conducting. Chlorella vulgaris biofilms were grown in the millimetre sized pores of the ceramic electrodes, producing an extensive extra cellular matrix that was anchored directly to the electrode surface. In contrast algal cells grown on carbon felt appeared misshapen and lacked a continuous extra cellular matrix. A preliminary comparison of different anodes in p-MFCs showed that the power density was ∼16 times higher on a ceramic anode compared to the best performing carbon anode. Good power densities were also found for algae grown directly onto FTO coated glass, but in contrast to the ceramic anodes the biofilm did not adhere strongly to the planar surface and was easily removed or damaged.