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The development of high activity, low-cost and stability hydrogen evolution reaction (HER) catalysts is a core issue in the field of water splitting. Herein, the bimetallic CoMo MOFs-derived N-doped carbon nanospheres with Co/Mo–N bonds is proposed to effectively improve the electrocatalytic HER performance. Meanwhile, the combination of the porous and spherical structure further promotes the effective contact on the electrode/electrolyte interface while enhancing the electrolyte into the inner structure of the material for a fast HER process. In addition, the N-doped and bimetallic Co/Mo oxides on the rough surface of nanospheres have the capability to furnish more electrocatalytic active sites. The obtained electrocatalyst owns the small overpotential of 112 mV at 10 mA cm−2 and Tafel slope of 106.8 mV dec−1 in 1.0 M KOH solution. This work provides a new prospect for the rational design and fabrication of bimetallic active sites in carbon nanomaterials electrocatalysts in the relevant energy applications. [Display omitted] • Bimetallic CoMo MOFs-derived N-doped carbon nanospheres is proposed to effectively improve the electrocatalytic HER performance. • The formation of Co–N and Mo–N, which would provide a fast electron transfer path in electrocatalytic process. • The formation of CoO and CoMoO 3 species could synergistic promote the adsorption and reaction of the H ads intermediates. [ABSTRACT FROM AUTHOR]

Fabrication of highly efficient and earth-abundant bifunctional electrocatalyst to accelerate the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are critical for overall water splitting. In this work, bimetallic Co/Mo oxides modified reduced graphene oxide (rGO) was synthesized using a simple one-pot hydrothermal method, which significantly improved the electrocatalytic activity in both HER and OER. Under the optimal conditions, the double layer capacitance of rGO modified by Co/Mo bimetal is 78.08 mF cm−2. The overpotential required for HER to reach -10 mA cm−2 current density is 488 mV, the dynamic Tafel slope is 126 mV dec−1. The overpotential required for OER to reach 10 mA cm−2 current density is 420 mV, the slope of kinetic Tafel is 169 mV dec−1. This work provides a new prospect for the rational design and fabrication of efficient HER/OER bifunctional electrocatalysts in electrochemical energy device application.Graphical Abstract: Fabrication of highly efficient and earth-abundant bifunctional electrocatalyst to accelerate the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are critical for overall water splitting. In this work, bimetallic Co/Mo oxides modified reduced graphene oxide (rGO) was synthesized using a simple one-pot hydrothermal method, which significantly improved the electrocatalytic activity in both HER and OER. Under the optimal conditions, the double layer capacitance of rGO modified by Co/Mo bimetal is 78.08 mF cm−2. The overpotential required for HER to reach -10 mA cm−2 current density is 488 mV, the dynamic Tafel slope is 126 mV dec−1. The overpotential required for OER to reach 10 mA cm−2 current density is 420 mV, the slope of kinetic Tafel is 169 mV dec−1. This work provides a new prospect for the rational design and fabrication of efficient HER/OER bifunctional electrocatalysts in electrochemical energy device application. [ABSTRACT FROM AUTHOR]