Electrochemical preparation and application of PANI/MWNT and PPy/MWNT composite anodes for anaerobic fluidized bed microbial fuel cell

Polyaniline (PANI)/multi-walled carbon nanotubes (MWNT) and polypyrrole (PPy)/MWNT composite anodes were first prepared using electrochemical cyclic voltammetry (CV) method. FTIR and SEM spectra proved that PPy/MWNT and PANI/MWNT were successfully modified on graphite rods, meanwhile, the modified mechanism was also investigated. EIS tests indicated that the Rct values for unmodified anode, PANI/MWNT anode and PPy/MWNT anode were 226.20, 87.93 and 34.95 omega, respectively, which meant that PPy/MWNT composite anode possessed best electrical conductivity compared with PANI/MWNT anode and unmodified anode. By using PPy/MWNT and PANI/MWNT modified anodes in AFBMFC, the maximum output power density improved by 65.13% and 45.59% compared to that of PPy anode and PANI anode, respectively. Meanwhile, the COD removal rates for the three anodes followed as PPy/MWNT anode > PANI/MWNT anode > PPy anode > PANI anode > unmodified anode.