In situ carbon felt anode modification via codeveloping Saccharomyces cerevisiae living-template titanium dioxide nanoclusters in a yeast-based microbial fuel cell

Titanium dioxide (TiO₂) nanoclusters grown in situ by Saccharomyces cerevisiae as a living-template atop a seeded and polyethylenimine functionalized carbon felt are explored for the first time for the enhanced performance of the anode within a yeast-based microbial fuel cell (MFC). Widespread, extensive, and synergistic growth of both the yeast biofilm and TiO₂ nanoclusters are observed on the hydrophilic surface of the functionalized carbon felt fibers. The entirely green and inexpensive process required only the use of a nanoparticle seed that also acts as the nanoparticle growth initiator: titanium(IV) oxide anatase. The structure and morphology of the TiO₂ nanostructures are examined through optical measurements after full experimentation within a yeast-based MFC system. Due to the extensive evocation of the exopolysaccharides matrix of the yeast through the well-timed introduction of the nanoparticle growth initiator, the yeast biofilm is beneficially affected by the presence of the TiO₂ nanoclusters, thus improving the yeast biofilm maturation and electrochemical behaviour. How the yeast biofilm reacts to the invasion of foreign metallic nanoparticles and how this is beneficial to MFC research are explored. The best power density of the MFC achieved through this method was 25.9 ± 6.2 W m⁻², an astounding value that far exceeds similar modification techniques to the MFC anode.