Performance Improvement of Microbial Fuel Cell with Polyaniline Dopped Graphene Anode

Abstract

Microbial fuel cell (MFC) technology has potential in recovering bioelectricity from different types of waste, which attracts more and more attention in the field of environment and energy. However, low power density, high cost and low substrate degradation rate, closely associated with anode performance, limit its practical application. In this study, proportional polyaniline (PANI) together with graphene was chosen to obtain the PANI dopped graphene composite. The as-received composite was modified onto the surface of glassy carbon electrode. The results of electrochemical analysis showed that the optimal mass ratio of graphene was 20% for cyclic voltammetry (CV) and linear sweep voltammetry (LSV) analysis. The anodes with 5% graphene produced a peak power density of (831±45) mW·m-2, which was 1.2, 1.3, 1.3, 1.5, 1.8 times of those with 20% graphene, 1% graphene, graphene, PANI and carbon cloth, respectively. Moreover, 5% graphene reactors showed the maximum values in output voltage, open-circuit voltage (OCV), chemical oxygen demand (COD) removal rate, coulombic efficiency (CE), and biomass density. The polarization resistance was only (24±2)Ω in 5% graphene reactors,which was 19.8% of that of carbon cloth. The results of electrochemical analysis were not consistent with those of bioelectrochemical analysis, demonstrating that the biocompatibility of electrode was one of the important factors affecting MFC performance. 5% graphene anode showed full advantages of graphene and PANI, which improved the performance of MFC.