Graphene-modified biochar anode on the electrical performance of MFC

Abstract

Improving the power output and other power generation performance is the technical bottleneck restricting the industrial application of microbial fuel cell (MFC). Modification of the anode using nanomaterials can significantly increase the power output of MFC. The negatively charged characteristics of Rhodopseudomonas palustris was utilized to propose electroplating of graphene on the surface of biochar, and preparation of polyaniline (PANI) modified biochar electrode by in situ polymerization. Thus, a graphene oxide/polyaniline modified biochar (GO/PANI@Biochar) anode was prepared. Thus, compared the effects of GO/PANI@Biochar, biochar, traditional carbon cloth (CC), and graphite felt (GF) anodes on the power generation performance of MFC. The results showed that the contact angle θ of the new anode was as low as 0°. The biocompatibility is good, and a large number of electricity-producing microorganisms adhere to the surface of the anode material. The maximum power density of GO/PANI@Biochar anode MFC reached to 2025 mW/m2, which was 72.12% higher than that of unmodified biochar, and it was 3.5, 4.39 times that of traditional GF and CC. The maximum output voltage was 6.12% higher than before modification, 15.56% and 23.8% higher than traditional GF and CC anodes. GO/PANI@Biochar anode utilized the advantages of GO conductivity and biochar high biocompatibility effectively. The synergism of them can significantly improve the current and power density of MFC.