Cathodic biofilm activates electrode surface and achieves efficient autotrophic sulfate reduction

Finally, exposing the biofilm to biocidal conditions (pH 3.0, air drying and autoclaving) led to a 27% reduction of the hydrogen production rate, which was nevertheless 5.3 times higher than a bare electrode. Energy dispersive x-ray spectroscopy (EDS) and protein electrode surface analyses revealed the presence of metallic and proteinaceous materials deposited on the surface after biocidal conditions, suggesting that the biofilm was able to modify the electrode surface towards more efficient hydrogen evolution reaction (HER).