Design of ZIF-67-derived Fe, N and F co-doped porous carbon material and evaluation of its ORR and OER performance

Addressing the low conductivity and porosity of ZIF-67-based oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalysts is a top priority. Noble metal-free highly active bifunctional catalysts F-N/FeCoNC900 with three-dimensional interconnected porous structure and high electrical conductivity were successfully prepared by co-doping Fe, F, and N on the precursor ZIF-67. In terms of ORR performance, F-N/FeCoNC900 has a high onset potential (Eonset) of 0.97 V (vs. RHE), a half-wave potential (E1/2) of 0.87 V (vs. RHE), and an ultimate current density (JL) of 5.7 mA cm−2, superior to commercially available Pt/C (0.95 V, 0.85 V, 5.3 mA cm−2). In addition, F-N/FeCoNC900 provides high ORR activity with constant 4 electron transfer (n = 3.91–3.99) for methanol resistance and long-lasting stability (initial current retention of 96.32% after 21600 s). In terms of OER performance, F-N/FeCoNC900 exhibits ultra-low overpotential (273 mV) and ultra-high Faraday efficiency (93%) at constant 4 (n = 3.91–3.99) electron transfer mode. This work provides a new pathway of doped ZIFs-derived composites as efficient bifunctional non-precious metal catalysts.