MnO2/Polypyrrole/MnO2 multi-walled-nanotube-modified anode for high-performance microbial fuel cells

Hierarchical multi-walled MnO2/polypyrrole/MnO2 nanotubes (NT-MPMs) were synthesized by a hydrothermal method and were decorated on a carbon cloth anode to promote microbial fuel cell (MFC) power production. Compared with bare carbon cloth (CK) anodes, the maximum power density of the MFC with an NT-MPM-decorated anode reaches 32.7 ± 3 W/cm3, which is approximately 1.3 times higher than that of the CK, and it exhibits excellent durability. The voltage outputs of the NT-MPM anode MFC decreased by 9.2% after being subjected to more than 90 full discharging-charging cycles. In additionbanode, which facilitated biofilm growth and promoted extracellular electron transfer between the bacteria and the electrode. Electrochemical impedance spectroscopy (EIS) measurements reveal that NT-MPM anodes lead to a low charge transfer resistance and provide unique active centers that host the bacteria for more efficient electrocatalysis. This study introduces a promising method for the fabrication of high-performance anodes from simple, inexpensive materials.