Investigation Of Nitrogen Modified Graphite Felts As The Anode Of Microbial Fuel Cell

Microbial fuel cells (MFC), used as a kind of environmentally friendly and renewable energy source have quickly developed in recent years. In MFC, the use of microorganisms as the catalysts oxidize organic (inorganic) matter and directly convert chemical energy into electricity. The biggest factor restricting the MFC output power density is electron transfer process. From the constituted of MFC, the research on MFC anode has very important significance. The ornament of anode materials using different kinds of nitrogenous compounds have been a successful technology.For the present work, we modified graphite felt anodes with different kinds of nitrogenous compounds including inorganic ammonium compounds (ammonium peroxydisulfate) and organic amine compounds (ethylenediamine, glycine, poly(N,N-dimethylaniline), polyaniline). The configuration of surface and surface functional groups were investigated using the scanning electron microscopy (SEM) and X-ray photoelectron spectrometry (XPS) techniques.The first experiment results showed the MFC with plain graphite felt (GF) achieved the maximum voltage of0.50-0.52V, the maximum power output was283mW/m2. The maximum power density of GF-A、GF-A1was510mW/m2and609mW/m2, respectively. XPS analysis data indicated the different treatment methods lead to the changes of N1s/C1s ratio that was consistent with the power density increases of MFCs.In the second part of the experiment, the maximum power density of GF-E、GF-G was355mW/m2and500mW/m2, respectively. Much rougher surface and deeper cracks on the modified anodes were observed. The amino groups have lone pair electrons, which increased the charge density on the electrode surface and promoted the electron transfer between the cell and the electrode, thus increasing the power density.In the third part of the experiment, and comparing to unmodified (321mW/m2), the maximum power density of GF-PANI and GF-PDMA MFCs could reach366mW/m2and333mW/m2. The results confirmed that poly(N,N-dimethylaniline) could be used as a good anode modifier for a microbial fuel cell.