N,S-Doped hollow carbon nanosheet-encapsulated Co9S8 nanoparticles as a highly efficient bifunctional electrocatalyst for rechargeable zinc–air batteries

A “MOF on MOF” strategy was proposed for the synthesis of N,S co-doped hollow carbon nanosheets embedded with Co 9 S 8 nanoparticles. The resulting material is a highly efficient bifunctional air electrode for Zn–air batteries.