Nitrogen-doped carbon encapsulating γ-MoC/Ni heterostructures for efficient oxygen evolution electrocatalysts.

Developing efficient and earth-abundant oxygen evolution reaction (OER) electrocatalysts is of great importance in renewable energy research. Herein, we report nitrogen-doped carbon encapsulating γ-MoC/Ni heterostructures (γ-MoC/Ni@NC) for the first time as efficient OER electrocatalysts. The composites can be controlled by the addition of a Mo source to form a nanoparticle-assembled hierarchically porous nanostructure, which can enlarge the specific surface area, thus exposing more active sites. Moreover, we demonstrate that the formation of γ-MoC@Ni heterostructures and the resulting synergistic effect between γ-MoC and Ni can facilitate the reaction kinetics, leading to significantly improved OER activity with an onset overpotential of merely 240 mV, and a low overpotential of 310 mV to afford a current density of 10 mA cm-2 . This work provides a new insight into the development of highly active and inexpensive OER electrocatalysts.