Multi-walled carbon nanotubes modified corn straw biochar as high-performance anode in microbial fuel cells

In this study, the feasibility of multi-walled carbon nanotubes in modifying corn straw biochar electrode and the subsequent enhancement in electrical conductivity of the modified electrode and reactor performance were investigated in this study. The Layer-by-Layer self-assembly method was used as the modification method. The electrochemical activity, power output capacity and pollutant removal performance of the Microbial fuel cell with modified corn straw biochar anode. The characterization techniques included scanning electron microscope, electrochemical impedance spectroscopy, Tafel analysis and polarization curve. The successful adhesion of multi-walled carbon nanotubes onto the surface of corn straw biochar was revealed by scanning electron microscope analysis. The microbial fuel cell with multi-walled carbon nanotubes modified corn straw biochar anode achieved the lowest solution resistance of 9.86 Ω and charge transfer resistance of 3.56 Ω. Compared with the MFC with unmodified electrode, power density (2.68 W m-2) and coulombic efficiency (70.52%) were demonstrated to increase by 58.6% and 24.6% in the MFC with modified electrode, respectively.