Nano-Fe₃C@PGC as a novel low-cost anode electrocatalyst for superior performance microbial fuel cells

We report a novel anode electrocatalyst, iron carbide nanoparticles dispersed in porous graphitized carbon (Nano-Fe₃C@PGC), which is synthesized by facile approach involving a direct pyrolysis of ferrous gluconate and a following removal of free iron, but provides microbial fuel cells with superior performances. The physical characterizations confirm the unique configuration of iron carbide nanoparticles with porous graphitized carbon. Electrochemical measurements demonstrate that the as-synthesized Nano-Fe₃C@PGC exhibits an outstanding electrocatalytic activity toward the charge transfer between bacteria and anode. Equipped with Nano-Fe₃C@PGC, the microbial fuel cells based on a mixed bacterium culture yields a power density of 1856 mW m^-2. The resulting excellent performance is attributed to the large electrochemical active area and the high electronic conductivity that porous graphitized carbon provides and the enriched electrochemically active microorganisms and enhanced activity towards the redox reactions in microorganisms by Fe₃C nanoparticles.