Which determines power generation of microbial fuel cell based on carbon anode, surface morphology or oxygen-containing group?

To clarify the role of carbon surface nature in the power generation of microbial fuel cell (MFC) based on carbon anode, three carbon felt samples, obtained by simple water cleaning (CCF), heating (HCF) and oxidation with ammonium persulfate (ACF), were characterized with SEM, BET, FTIR, cyclic voltammetry and acid titration, and their performances as anode of MFC were investigated with polarization curve measurement, chronoamperometry and chronopotentiometry. It is found that the power output of MFC depends on the morphology rather than the oxygen-containing group concentration of the carbon felt surface. CCF, HCF and ACF have their surface oxygen-containing groups of 1.52, 0.8 and 0.45 mM m−2 and specific surface areas of 0.33, 0.65 and 1.19 m2 g−1, but yield their maximal power densities of 606, 858 and 990 mW m−2, respectively. This study suggests that intensive attention should be paid to the design of surface morphology in order to improve power generation of MFC.