Development of Graphene-based novel cathode material in MES system

It has been reported that physical contact between unique nanostructures of electrode and bacteria isimportant for microbial electrosynthesis. The higher specific surface area of cathode can increase contact interface area with bacteria and enhance electron-exchange at the electrode surface.The graphene (GP) has outstanding electrical conductivity, extremely high specific surface area,mechanical robustness and flexibility, chemical inertness, and biocompatibility. These special properties ofGP can provide excellent opportunity to improve the performance of MES. Gram negative microorganisms like Sporomusa ovata (S.O) typically have a negative outer-surface charge. The graphene oxide (GO) is the acceptor of the electron. If the GO accept electrons from the Sporomusa ovata and the GO can be reduced to graphene. This will lead to in situ construction of a bacteria/graphene network in the cathode. This enable the incorporation of a large amounts bacteria into the biofilm matrix, and form multiplexed conductivepathways, thus facilitating electron exchange between bacteria and electrode. The images of GO, the R-GO, can be characterized and analyzed by SEM or AFM. We can also use the methods of XRD, XPS and RamanSpectrum to character the GO and R-GO. The density of the Sporomusa ovate on the R-GO cathode can becharactered by the confocal laser-scanning fuorescence microscopyer. Acetate is measured via high performance liquid chromatography (HPLC). The images of R-GO/Sporomusa ovate can be characterizedand analyzed by SEM or AFM. Thanks to the high surface area for graphene, superior conductivity, biocompatibility, the incorporation of the large amount bacteria into the biofilm matrix, and forming multiplexed conductive pathways, so the hybrid biofilm can facilitate electron exchange between bacteria and electrode. It will be expected that R-GOcan improve microbe–electrode electron exchange and can effectively enhance microbial electrosynthesisrates