BACKGROUND: For a microbial fuel cell (MFC), the anode material plays a crucial role in power output. RESULTS: A dual-chamber MFC was constructed using carbon cloth (CC) anodes treated by concentrated nitric acid (CC-A) and heated in a muffle furnace (CC-H), respectively. The experiment results showed that the stable maximum voltages were 0.420.46 V for CC, 0.520.58 V for CC-A and 0.80 V for CC-H under the condition of a 1000 external resistance, which were much higher than those reported in the literature so far. Moreover, the maximum power density of the CC-H anode (687 mW m2) was larger than for the CC-A anode (480 mW m2) and the CC anode (333 mW m2). Electrochemical impedance spectroscopy (EIS) results revealed that the internal resistance was 251 for CC anode, 202 for CC-A anode and 162 for CC-H anode. Scanning electron microscopy (SEM) results indicated that the increase of power generation was attributed to the increase of bacteria counts attached to anodes. The power output of the MFC increased along with the increase of the N1s/C1s ratio, which was proved by X-ray photoelectron spectroscopy (XPS) analysis. CONCLUSIONS: Carbon cloth anodes treated by concentrated nitric acid and high temperature resulted in improved power generation by a microbiol fuel cell. (c) 2012 Society of Chemical Industry