The feasibility of typical metal–organic framework derived Fe, Co, N co-doped carbon as a robust electrocatalyst for oxygen reduction reaction in microbial fuel cell

Abstract

Several iron and cobalt dual metal- and nitrogen-doped carbons (FeCoNCs) are synthetized by using a typical metal–organic framework, ZIF-67, as the precursor for oxygen reduction reaction. With the rise of pyrolysis temperature (700 °C–1000 °C), the morphological evolution and structural changes of resultant FeCoNC samples and the subsequent differences in oxygen reduction performances were also explored. The maximum power density of the FeCoNC-modified air-cathode microbial fuel cell (MFC) reaches 1769.95 mW m−2, which is superior to that of Pt/C-modified MFC (1410.31 mW m−2). A N2 adsorption–desorption experiment reveals the presence of abundant mesoporous in the structure of the as-prepared FeCoNC material pyrolized at 900 °C (FeCoNC-900), and the Brunauer–Emmett–Teller model discloses its high specific surface area. Rotating disk electrode test results demonstrate a four-electron transfer pathway for the FeCoNC-900 catalyst. Furthermore, the MFC device modified by the as-prepared FeCoNC materials shows excellent durability and stability as cathode oxygen reduction catalyst.