Interfacial engineering and chemical reconstruction of Mo/MoC@CoO@NC heterostructure for promoting oxygen evolution reaction.

Chemical reorganization and interfacial engineering in hybrid nanomaterials are promising strategies for enhancing electrocatalytic performance. Herein, MoO@zeolitic imidazolate framework-67 (ZIF-67) heterogeneous nanoribbons are designed through coordination assembly. By following heat treatment, a Mo/MoC@CoO@NC heterostructure with nitrogen-doped carbon-encapsulated CoO hexagons (CoO@NC) anchored on the Mo/MoC jag matrix was fabricated. Notably, through controllable experimental optimization, the as-prepared Mo/MoC@CoO@NC heterostructure exhibits numerous active centers ( Mo, MoC, CoO, and NC), fully exposed active sites (numerous pores and jagged structures), and abundant heterointerfaces (Mo/MoC, MoC/CoO@NC, MoC/amorphous, and CoO@NC/amorphous), and exhibits good conductivity (localized single-crystal behavior, graphitized carbon). As a result, the as-developed Mo/MoC@CoO@NC heterostructures inherit impressive oxygen evolution reaction (OER) performance with an overpotential of only 215 mV at 10 mA cm. Furthermore, Mo/MoC@CoO@NC heterostructures exhibit excellent stability with a current density retention of 98.4% after 20 h chronoamperometry. This work provides deep insights into chemical reconstructions and tuning heterointerfaces to efficiently enhance the OER activity of heterostructure-based electrocatalysts.