Cobalt-based Catalysts Modified Cathode for Enhancing Bioelectricity Generation and Wastewater Treatment in Air-breathing Cathode Microbial Fuel Cells

To seek an efficient way to enhance the power output and wastewater treatment of microbial fuel cell (MFC), several cobalt-based composites are successfully synthesized by a facile hydrothermal method under different pyrolysis temperature, and these composites are used as electrocatalyst in air-breathing cathode of MFC. Different species of nitrogen atom are successfully grafted on the cobalt-based composites and confirmed by physical and electrochemical analyses. In MFC tests, the maximum power density increases from 577.8 mW m(-2) to 931.1 mW m(-2) with pyrolysis temperature (except for 1000 degrees C). These electrochemical tests and high COD removal show that Co/N/C-900 can rapidly transfer electron via a 2x2 e(-) transfer pathway, mainly due to the exposure of large electrochemical active area and introduction of the defects of pyridinic-N and abundant oxygen vacancies. Although the power density of MFC with Co/N/C-900 is 81.1 % of that of commercial Pt/C, the MFC with Co/N/C-900 is more stable than that of Pt/C, and the power density for Co/N/C-900 has only a 2.8 % decrease during 25-cycles operation. The great electrocatalytic activity of the novel Co/N/C-900 composite exhibits a superior outlook for scale-up application of MFC in the future.