Nickel-Cobalt oxides coated on polypyrrole nanotubes as bifunctional electrode catalyst for enhancing the performance of the microbial fuel cells

The surface modification of electrodes is a vital technique for improving the power output of microbial fuel cells (MFCs). In this study, a single bifunctional catalyst material, Nickel (Ni)-cobalt (Co) oxides coated on polypyrrole nanotubes (PNT) (NiCo2O4@PNT), is prepare and used as the electrode catalyst material for a single chambered MFC. The catalyst show excellent oxygen reduction reaction (ORR) activity and work as a good electron acceptor at the anode. The electrocatalytic activity of the prepared catalyst is inspected by cyclic voltammetry (CV), which showed the highest reduction peak for NiCo2O4@PNT at 0.0621 mA. Four different catalysts have been prepare in this study NiCo2O4@PNT, NiO@PNT, CoO@PNT and PNT. The maximum power density of NiCo2O4@PNT is 427.52 mW/m2 (anode) and 916.12 mW/m2 (cathode), which is significantly higher than those of the other catalysts. These results suggest that NiCo2O4@PNT is a promising bifunctional catalyst for MFCs.