Engineering interfacial coupling between Mo2C nanosheets and Co@NC polyhedron for boosting electrocatalytic water splitting and zinc-air batteries

The noble-metal-free trifunctional electrocatalysts consisting of vertically aligned Mo2C nanosheets on the surface of Co@NC polyhedron have been presented for efficient water splitting and metal-air batteries. The reciprocally permeated structure and strong interfacial coupling effects between Mo2C and Co@NC significantly improve the intrinsic activities and accessible active sites toward hydrogen evolution reaction, oxygen evolution reaction and oxygen reduction reaction. [Display omitted] •A facile method has been developed for the fabrication of Mo2C nanosheets on the surface of Co@NC polyhedron.•The interface effect between polyhedron and nanosheet significantly improves the electrochemical performance.•The heterostructure materials serve as trifunctional electrocatalysts for efficient water splitting and metal-air batteries. The cost-effective and durable electrocatalysts for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is vital to overall water splitting and regenerative metal-air batteries. Herein, we presented a simple metal-organic framework (MOF)-based approach for facile fabrication of noble-metal-free trifunctional heterostructure electrocatalysts. Different from traditional MOF-derived composite materials, Mo2C nanosheets are vertically aligned on the surface of cobalt-embedded nitrogen-doped carbon polyhedron (Mo2C/Co@NC). Benefiting from the reciprocally permeated structure and strong interfacial coupling effects between Mo2C nanosheets and Co@NC polyhedron, the intrinsic activities and the accessible active sites toward HER, OER and ORR are significantly improved, which endows Mo2C/Co@NC with high electrocatalytic activity and durability as a trifunctional electrocatalyst. Notably, Mo2C/Co@NC-based Zn-air battery could efficiently power the electrochemical water splitting using Mo2C/Co@NC as the electrodes. This work provides one heterostructural protocol to construct new types of noble-metal-free trifunctional electrocatalysts for boosting water splitting and zinc-air batteries.