Carbon Nanotube-Encapsulated Fe ₂ P Catalysts Featuring Fe ₂ P-Mo ₂ C Heterointerfaces for Oxygen Reduction in Microbial Fuel Cells

Insufficient catalytic activity and poor durability of the oxygen reduction reaction (ORR) hinder the efficient and durable operation of microbial fuel cells (MFCs). In this work, an ORR catalyst Fe 2 P-Mo 2 C@NC was prepared by one-step pyrolysis using an Fe/Mo co-modified ZIF-8 precursor with phytic acid-assisted etching. Fe 2 P-Mo 2 C heterointerfaces induced electronic interactions and modulation of the local electronic environment. Mo doping was associated with the formation of a more continuous CNT network and promoted the encapsulation of Fe 2 P nanoparticles. The ZIF-derived carbon framework and CNT networks formed continuous conductive pathways and facilitated charge transport within the catalyst. Fe 2 P-Mo 2 C@NC exhibited excellent ORR activity with a half-wave potential of 0.89 V and a dominant four-electron pathway. The MFC assembled with Fe 2 P-Mo 2 C@NC maintained stable operation for up to 200 h in a single cycle and delivered a maximum power density of 1480 mW m −2 . This work offers a viable strategy for designing efficient and durable ORR catalysts for MFC cathodes.