Positive regulation of active sites for oxygen evolution reactions by encapsulating NiFe 2 O 4 nanoparticles in N-doped carbon nanotubes in situ to construct efficient bifunctional oxygen catalysts for rechargeable Zn–air batteries

Benefitting from the structure of NiFe 2 O 4 nanoparticles encapsulated in N-doped carbon nanotubes, the Fe–Me–Ni exhibits excellent catalytic activities for ORR and OER, and superior long term discharge–recharge durability.