MOF derived Ni-Fe based alloy carbon materials for efficient bifunctional electrocatalysts applied in Zn-air battery

Bimetallic electrocatalysers have attracted dramatic attentions in recent years owing to their unique electronic configuration, charge transfer efficiency and synergistic effect. Ni-Fe based alloys are considerable as one of the most promising materials with superior electrocatalytic performance since the outstanding oxygen reaction activity of iron and the strong capability of nickel. Herein, Ni-Fe MOF derived Ni-Fe alloys embedded graphitic carbon electrocatalyst is synthesized as bifunctional oxygen electrocatalyst with hierarchical porous structure and superior oxygen reaction electrocatalytic performance. The onset potential and the half-wave potential of Ni0.6Fe0.4 CM in oxygen reaction are 0.88 V and 0.75 V, respectively, which are superior than those of commercial Pt/C. Furthermore, a low overpotential of 320 mV at 10 mA/ cm2 is obtained in oxygen evolution reaction, which is well consistent with that of commercial RuO2. In the meantime, excellent long-term stability and anti-methanol ability endow Ni0.6Fe0.4 CM exhibiting brilliant electrocatalytic performance as commercial Pt/C and RuO2. The assembled Zn-air battery exhibits smaller voltage gap (0.76 V) than that for commercial Pt/C and RuO2, and it has remarkable stability around 170 cycles in the discharge–charge test. These results summarize the merits of bimetallic electrocatalysers for bifunction electrochemical performance and promote the development of electrocatalytic applications.