Fig. 3. (a) Diagram of the MFC chamber components. Photographs of the aerogel disks: (b) a A-CMC, (c) PD A-CMC–PD, (d) A-CMC–Gr and (e) A-CMC–Gr–PD. (f) SEM micrograph of R. palustris biofilm on the anode. (g) A simplified diagram illustrating the oxidation of substrate metabolites to provide reducing power that is transferred to the anode through a circuit to the cathode via a potentiostat. To balance charges, mass transport of protons also generated from metabolism occurs through a proton exchange membrane to the air exposed catalytic side of the cathode membrane, where they combine with electrons and atmospheric oxygen to form water.
