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

► We show the first finding that RuO2 represents a favorable anode material of MFCs. ► Incorporation of RuO2 significantly enhances extracellular electron transfer. ► A maximum power density of 3.08 W m−2 was obtained. ► To our knowledge, it represents a high value ever reported for a dual-chamber MFC.