Facile synthesis of nitrogen and fluorine co-doped carbon materials as efficient electrocatalysts for oxygen reduction reactions in air-cathode microbial fuel cells

Abstract

Nitrogen and fluorine co-doped carbon black (BP-NF) was prepared via the direct pyrolysis of a mixture of polytetrafluoroethylene (PTFE) and BP-2000 under an ammonium atmosphere for high efficient ORR electrocatalysis in the air-cathode of microbial fuel cells (MFCs). The electrocatalytic activity of BP-NF is higher than that of single nitrogen or fluorine doped carbon materials (BP-N, BP-F), with an onset potential of E = 0.2 V (BP-NF), E = 0.1 V (BP-N), and a limiting current density of I = 4.5 mA cm⁻² (BP-NF), I = 0.31 mA cm⁻² (BP-F), respectively. The results demonstrated a synergistic ORR catalytic effect in N and F co-doping carbon material. The maximum power density of MFC with BP-NF as the cathode catalyst (672 mA cm⁻²) was higher than that with commercial Pt/C (572 mA cm⁻²).