Macroporous carbon foam with high conductivity as an efficient anode for microbial fuel cells

Abstract

In this work, we demonstrate graphitized mesophase pitch-based carbon foam as anode for microbial fuel cells for the first time. Graphitized mesophase pitch-based carbon foam (GMCF), mesophase pitch-based carbon brush (MCB), pitch-based carbon felt (CF) with the different structures are investigated. Among them, GMCF-MFC exhibits excellent power generation property of 1800 mW/m2, which is 1.33 and 2.65 times that of MCB-MFC and CF-MFC. GMCF is a graphitized material with a high electrical conductivity that accelerates extracellular electron transport (EET) between microorganisms and the surface of the material, thereby improving the electrochemical performance of MFCs. Besides, GMCF has well-developed macroporous (almost 300 μm in diameter) and through-pore structures, which could facilitate the enrichment of microorganisms and the diffusion of ions. And the staggered through-pores fix exoelectrogens in the pores, preventing them from “swimming out” and promoting the formation of microbial communities in these pores. More importantly, GMCF is a low-cost rigid carbon foam that can be easily fabricated into large-sized electrodes, which is beneficial for application to MFC amplification tests.