Carbon paper electrode modified by goethite nanowhiskers promotes bacterial extracellular electron transfer

• A composite electrode consists of goethite nanowhiskers and carbon paper.
• Intercrossed α-FeOOH nanowhiskers form open porous layer on electrode surface.
• Current density produced by PV-4 on composite electrode was increased by 60%.
• A feasible way to obtain high performance bio-anodes made of ordinary materials.

A novel composite anode α-FeOOH–NWs/CP was fabricated by growth of α-FeOOH nanowhiskers (NWs) on the surface of carbon paper (CP) through facile hydrothermal reaction. The intercrossed α-FeOOH NWs were about 30–50 nm in diameter and 500–800 nm in length, formed open pores on the CP surface. The composite electrode markedly facilitated bacterial extracellular electron transfer in the cell containing the strain PV-4. The current density of 0.48 A/m2 on α-FeOOH–NWs/CP was 60% higher than that of 0.30 A/m2 on bare CP after 42 h cultivation of PV-4, which was attributed to better growth of PV-4 and lower charge transfer resistance. The result shows a feasible way to obtain an inexpensive anode with high biocompatibility and bio-electrocatalytic activity.