Ruthenium oxide-coated carbon felt electrode: A highly active anode for microbial fuel cell applications

Abstract

Enhancing the anode performance is a critical step for improving the power output of microbial fuel cells (MFCs). This study presents an active anode that involves the use of ruthenium oxide (RuO2)-coated carbon felt electrode for MFC applications. Cathodic electrodeposition was performed to decorate the carbon felt surface with the RuO2 films composed of submicron-/nano-sized particles. Increasing the amount of charge applied for the electrodeposition resulted in the increase in power performance of MFCs that were inoculated either with the pure culture or the mixed microbial consortia. The dual-chamber MFC equipped with the RuO2-coated anode reached the maximum power density of 3.08Wm−2 (normalized to the projected area of anode), increased by 17 times as compared to that obtained with the MFC with the bare anode. Cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) results provided evidence that there was a substantial improvement in electron transfer between the microbes and the anode. The results demonstrate that RuO2 interacts electrochemically with the cells and has ability to facilitate extracellular electron transfer.