Improved cathode for high efficient microbial-catalyzed reduction in microbial electrosynthesis cells

Abstract

Microbial electrosynthesis cells (MECs) are devices wherein microorganisms can electrochemically interact with electrodes, directly donating or accepting electrons from electrode surfaces. Here, we developed a novel cathode by using nickel nanowires anchored to graphite for the improvement of microbial-catalyzed reduction in MEC cathode chamber. This porous nickel-nanowire-network-coated graphite electrode increased the interfacial area and interfacial interactions between the cathode surface and the microbial biofilm. A 2.3 fold increase in bio-reduction rate over the untreated graphite was observed. Around 282 mM day⁻¹ m⁻² of acetate resulting from the bio-reduction of carbon dioxide by Sporomusa was produced with 82 ± 14% of the electrons consumed being recovered in acetate.