Exploring stable and highly efficient bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is critical for the novel energy conversion and storage devices including fuel cells and metal-air batteries. Herein, the core-shell structured Co₃Fe₇@Fe₂N nanoparticles supported on reduced graphene oxide (rGO) nanosheets (Co₃Fe₇@Fe₂N/rGO) is designed though the simple annealing of MOFs. The as-fabricated samples present an excellent electrocatalytic performance for ORR and OER due to the synergistic effect of electrode materials. The Co₃Fe₇@Fe₂N/rGO exhibits an onset potential of 0.98 V (vs. Reversible hydrogen electrode), peak current intensity of 1.531 A g⁻¹ and long-term stability for ORR, which is close to that of the benchmark Pt/C (20%) in 0.1 M KOH. It also shows good oxygen evolution reaction (OER) performance with an overpotential of 371 mV (at 10 mA cm⁻²). When used as a bifunctional air electrode in Zn-air batteries, the core-shell materials enabled an excellent mass power density of 60 W cm⁻² g⁻¹ at 0.57 V and stable cycling performance for over 100 cycles.

探索用于氧还原反应（ORR）和氧释放反应（OER）的稳定高效的双功能电催化剂，对于包括燃料电池和金属空气电池在内的新型能量转换和存储设备至关重要。本文中，通过MOF的简单退火，设计了在还原的氧化石墨烯（rGO）纳米片上负载的核-壳结构的Co ₃ Fe ₇ @Fe ₂ N纳米颗粒（Co ₃ Fe ₇ @Fe ₂ N / rGO ）。由于电极材料的协同作用，制成的样品对ORR和OER具有出色的电催化性能。Co ₃ Fe ₇ @Fe ₂N / rGO的起始电势为0.98 V（相对于可逆氢电极），峰值电流强度为1.531 A g ^-1，ORR的长期稳定性接近于基准Pt / C（20％）在0.1 M KOH中 它还显示出良好的氧气释放反应（OER）性能，过电势为371 mV（在10 mA cm ^-2时）。当用作Zn-空气电池中的双功能空气电极时，核-壳材料在0.57 V时具有60 W cm ^-2  g ^-1的出色质量功率密度，并在100个以上的循环中具有稳定的循环性能。