Microbial fuel cell based on iron modified carbon nanofiber anode

Iron modified carbon nanofibers（Fe@CNF） were prepared by electrospinning and simple high temperature carbonization with iron acetylacetonate as iron source. The Fe@CNFs were applied to Shewanella S. putrefaciens CN32 microbial fuel cells to promote the interfacial electron transfer process in anode. The results show that the Fe@CNFs possess nanopores of 2～10 nm, which significantly increases the specific surface area so that they can provide more active sites for interfacial electrochemical reaction. In addition, the content of low valent iron in Fe@CNFs increases with the increase of iron source content in the precursor. As a result, the Fe@CNF-III anode that containing highest ratio of low valent iron obtains the best performance in microbial fuel cells. Electrochemical analysis data and electrode morphology observation reveal that the reason may be that the increase of low valent iron content promotes the formation of electroactive biofilm on the electrode surface and the interfacial electron transfer between S. putrefaciens CN32 cells and the electrode.