Construction of a Single-chamber Direct Microbial Fuel Cell and Preparation of Cathode Electrode

A new type of single-chamber direct microbial fuel cell was constructed successfully on the basis of studying the cathode electrode containing Fe3+.The electricity generation mechanism of the single-chamber microbial fuel cell and the effect of different Fe3+contents on cell voltage in the cathode electrode were studied through experiments.By analyzing the cell voltage measured by the acquisition system,it is proved that the single-chamber direct microbial fuel cell is feasible,microbial electricity generation is mainly attributed to the electrochemically and biologically active cells attached to the electrode.The use of an Fe3+-graphite cathode enhanced the oxidation-reduction efficiency.Electron transfer driving force was generated in coupling of Fe3+ reduction to Fe2+ on the cathode.The Fe2+ cations were subsequently oxidized by O2 in air.For this Fe3+ circular effect,the electron transfer and oxidation-reduction efficiency were enhanced.The power density of the single direct microbial fuel cell was up to 14.58 mW/m2.