High performance of microbial fuel cell afforded by metallic tungsten carbide decorated carbon cloth anode

Abstract

Developing high efficient anode is of great significances for the application of microbial fuel cells. Tungsten carbide attracts our attention due to its platinum-like metallic conductivity, corrosion resistance and low cost. In this work, tungsten carbide nanoparticles are pasted on carbon cloth as the anode for mediator-less microbial fuel cell. The surface of obtained anode is quickly attached with highly dense biofilm that accounts for a fast extracellular electron transfer rate. Microbial community structure analysis at the genus level shows that the main exoelectrogens are Geobacter, Geothrix and Pseudomonas, all of which can completely decompose acetate and transfer electrons through both direct and indirect extracellular electron transfer pathways. Consequently, it contributes to higher power density (3.26 W m−2), better chemical oxygen demand removal rate (95.5%) and greater coulombic efficiency (83.2%), which are 2.14-fold, 1.22-fold, 1.71-fold of that obtained by the naked carbon cloth anode (1.52 W m−2, 78.1%, 48.6%), respectively. Especially for the coulombic efficiency, it is obviously higher than others’ reported works in the similar microbial fuel cells system, being attributable to the synergistic effect of exoelectrogen. In virtue of the above advantages, tungsten carbide is a potential candidate for the further application of microbial fuel cells.