Bioelectrochemistry without potentiostat (or any electronics)
Résumé
In recent years, we have been interested in performing electrochemistry without potentiostat, i.e. without providing electrical energy as input for running the bioelectrochemical reaction, and without recovering the produced energy, because the potential difference between the involved redox reactions was too low to be meaningfully exploitable and also because maximizing the current density was preferable to maximizing the power density. In practice, two electrodes are simply short-circuited at the same potential, but still specialize into anode and cathode due to differences in the local environment or the nature of the electrode surface. After a brief overview of this concept in the literature, I would like to present three examples of bioelectrochemistry performed without potentiostat for, 1) nitrate reduction with microbial electrodes, 2) biohydrogen production from organic waste and 2) NADH regeneration with H2. The methodology for characterizing the short-circuited system will be discussed and the main results will be highlighted.