Bimetallic hybrids modified with carbon nanotubes as cathode catalysts for microbial fuel cell: Effective oxygen reduction catalysis and inhibition of biofilm formation

Abstract

As a promising energy conversion equipment, the performance of microbial fuel cell (MFC) is affected by slow kinetics of oxygen reduction reaction (ORR). It is of great significance to explore electrocatalysts with high activity for sustainable energy applications. Herein, we synthesize the in-situ grown carbon nanotubes decorated electrocatalyst derived from copper-based metal organic frameworks (MOFs) co-doped with cobalt and nitrogen (CuCo@NCNTs) through straightforward immersion and pyrolysis process. The carbon nanotubes produced by metallic cobalt and high-activity bimetallic active sites formed by nitrogen doping enable CuCo@NCNTs to have the best oxygen reduction reaction (ORR) performance in alkaline electrolyte, with limit current density of 5.88 mA cm−2 and onset potential of 0.91 V (vs. RHE). Moreover, CuCo@NCNTs nanocomposite exhibits obvious antibacterial activity, and inhibiting the biofilm on cathode surface in antibacterial test and biomass quantification. The maximum power density (2757 mW m−3) of MFC modified with CuCo@NCNTs is even higher than Pt/C catalyst (2313 mW m−3). In short, CuCo@NCNTs nanocomposite can be an alternative cathode catalyst for MFC.