Hierarchical CoO@MoN heterostructure nanowire array as a highly efficient electrocatalyst for hydrogen evolution

The high energy barrier and sluggish electron transfer are regarded as the most important reasons that restricting the performance of electrocatalysts for hydrogen evolution. The hierarchical CoO@MoN heterostructure nanowire array is fabricated, with adjusted electronic structure for tuning the binding strength of intermediates. As a result, CoO@MoN exhibits an excellent activity that is close to the benchmark Pt/C toward hydrogen evolution in alkaline medium. The theoretical computations indicate that the coupling of CoO and MoN can lead to the facilitated electron transfer for the tuned band structure. Besides, the energy barrier in the reaction is greatly reduced for the ameliorated binding strength of intermediates on CoO@MoN. This work demonstrates the significance of accelerating the electron transfer and reducing the energy barrier by rationally constructing the heterostructure, which paves the road to the exploitation of highly active and cost-efficient electrocatalysts for hydrogen evolution.