Effect of the modified anode by graphene-multi walled carbon nanotubes composites material with resazurin on the performance of microbial fuel cells

Abstract:

[Objective] The anode modified with graphene-multi walled carbon nanotube composite materials was used to enhance the performance of microbial fuel cell (MFC). [Methods] The composite-material of resazurin (R/CC), resazurin+graphene (R+GNS/CC), resazurin+multi walled carbon nanotube (R+MWCNT/CC) and resazurin+graphene+multi walled carbon nanotube (R+GNS+MWCNT/CC) were dropped on the surface of carbon cloth electrode. [Results] The maximum MFC output voltages of R+GNS/CC (87 mV), R+MWCNT/CC (145 mV), R+GNS+MWCNT/CC (275 mV) were increased by 61.11%, 168.25% and 409.26% and the degradation rate of perchlorate were also increased by 59.1%, 89.7%, 147.3%, respectively. The results of electrochemical impedance (EIS) and Tafel for the four anode materials implied that the anode resistance of R+GNS/CC, R+MWCNT/CC, R+GNS+MWCNT/CC were decreased relative to that of R/CC, and electrode reaction rate were increased, but R+GNS+MWCNT/CC had smaller anode electrode activation resistance and faster reaction rate. At the same time, the extracellular polymeric substances analysis of microorganism on the four anode surface indicated that the amount of microorganism and polysaccharide increased and decreased respectively, R+GNS+MWCNT/CC anode is better for electron transfer. [Conclusion] The modified anode by graphene-multi walled carbon nanotubes composites material with resazurin decreased the resistance of MFC and enhanced the electron transfer rate.

Key words:Microbial fuel cell, Anode modification, Resazurin, Graphene, Multi walled carbon nano tubes