Electrostatic self-assembly of copper oxide nano catchers boosting the efficiency of oxygen reduction in microbial fuel cell

A nano-catcher mesh CuO/CNTs composite is employed as an oxygen reduction reaction (ORR) catalyst in air-cathode microbial fuel cell (MFC) and is synthesized through electrostatic self-assemble by combining the polyhedral CuO with Multi-walled Carbon Nanotubes (CNTs) which are used to construct an inter woven three-dimensional network structure. The experimental results show that the MFC using CuO/CNTs catalyst maintains a steady maximum output voltage of about 320 mV and a peak power density of 239.41 mW m⁻² within five cycles. The COD removal rate reaches 94.89 %, with a coulombic efficiency (CE) of 13.98 %, on par with commercial Pt/C. Density functional theory (DFT) predictions indicate that the semiconductor properties of CuO and the high conductivity of CNTs synergize to provide abundant active sites for the ORR and significantly enhance the efficiency of charge transfer. CuO/CNTs not only exhibit excellent catalytic activity and stability, but also demonstrate good methanol tolerance.