Efficient Bifunctional Oxygen Electrocatalysts for Rechargeable Zn−air Batteries Derived from Ni‐modified Prussian Blue.

The rational design and exploration of efficient, low‐cost and durable bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are key to the development of rechargeable metal−air batteries. Here, we report a novel approach to in‐situ synthesize Fe0.64Ni0.36 nanoalloy encapsulated in nitrogen‐doped porous carbon nanotubes (FeNi@N−CNTs) as bifunctional electrocatalyst derived from Ni‐modified Prussian blue, on which the ORR/OER can be promoted by the N−CNTs surface due to the electron modulation caused by electron transfer from the inner FeNi nanoalloy to the N−CNTs surface. The abundant wide‐size range of mesopores in N−CNTs can offer rapid mass transport channels to facilitate the catalytic reactions. In addition, the encapsulation structure endows the outer N−CNTs acting as a "shield" to prevent the inner FeNi nanoalloy from corrosion in strong basic medium. Thanks to the synergistic effect between the N−CNTs and FeNi nanoalloy, the obtained FeNi@N−CNTs exhibits excellent bifunctional oxygen catalytic activity together with outstanding performance and cycling durability in rechargeable Zn−air battery. This work will open new avenues for the development of advanced bifunctional electrocatalysts for other metal−air batteries. [ABSTRACT FROM AUTHOR]