Dual MOF-derived Fe, Co, N co-doped nanocomposite as efficient bifunctional electrocatalyst for oxygen

Metal-organic framework (MOF)-derived carbon nanocomposites have been widely applied in electrocatalytic fields due to their simple synthesis, excellent conductivity, and high catalytic activity. In this study, ZIF-67 and MIL-101(Fe) were synthesized via liquid-phase precipitation and solvent thermal methods, respectively. Then, the two kinds of MOFs were ground and calcined with melamine to prepare flower-like carbon nanocomposites. Under the optimal conditions, the oxygen reduction reaction (ORR) onset potential (E onset  = 1.019 V vs. reversible hydrogen electrode, RHE) and half-wave potential (E 1/2  = 0.866 V) of this prepared composite are both higher than those of commercial Pt/C catalyst (E onset  = 0.971 V, E 1/2  = 0.838 V). The prepared nanocomposite exhibits a lower oxygen evolution reaction (OER) overpotential (η = 338 mV at 10 mA cm −2 ) than RuO 2 (η = 372 mV), demonstrating superior catalytic performance. The prepared nanocomposite achieves simultaneous enhancement in both ORR and OER bifunctional catalytic performances. The power density of a zinc-air battery (ZAB) assembled with the optimal nanocomposite was 2.65 times higher than that of the Pt/C + RuO 2 system. This study establishes a fundamental framework for the rational design of high-performance ORR/OER bifunctional catalysts, while pioneering new avenues for ZAB technology commercialization.