Energetic Mof-Derived Hollow Carbon Tubes with Interconnected Channels and Encapsulated Nickel-Cobalt Alloy Sites as Bifunctional Catalysts for Zn–Air Batteries with Stable Cycling Over 600 Cycles

Energetic metal–organic frameworks (EMOFs) and EMOF-derived materials are currently a hot spot to replace precious-metal electrocatalysts. Here, the reasonable strategy and synthesis of an inventive class of alloy@C materials from EMOFs via one-step pyrolysis is reported as the first example. The freshly progressive NiCo@C with a individual hierarchical structure, being composed of uniformly distributive metal alloy nanoparticles (MANPs) decorated by N-doped porous hollow carbon nanotubes (HCNTs), displays extraordinary bifunctional catalytic activities for oxygen reduction and oxygen evolution reactions (ORR and OER) than that of commercial precious-metal catalysts. Experimental characterizations and theoretical calculations reveal the vital role of Ni-Co alloy doping in adjusting both performances. Moreover, as an air electrode in Zn–air batteries, NiCo@C demonstrates a large peak power density of 170 mW cm−2 and superior long-term stability over 600 cycles. In consideration of the expansive category of EMOFs and the governable fixation of single/multiple metal particles, this strategy gives evidence of a capacious scientific range.