Rational design of NiFe LDH@Ni3N nano/microsheet arrays as bifunctional electrocatalyst for overall water splitting

Low-cost, efficient and stable electrocatalysts are required for large-scale production of hydrogen by industrial scale water electrolysis. We report here a hybrid bifunctional electrocatalyst, composed of amorphous NiFe LDH nanosheets and metallic Ni3N microsheet arrays grown on Ni foam for water splitting in alkaline electrolyte. This electrocatalyst possesses typical 3D hierarchical heterostructure architecture and affords abundant exposed active sites. The strong coupling and synergistic effects between the NiFe LDH and the Ni3N microsheet arrays endue a robust integrated structure and fast electron transfer. The superhydrophilic/superaerophobic properties of the electrocatalyst promote the mass transfer especially at a large current density. By employing the NiFe LDH@Ni3N/NF as bifunctional electrocatalysts for overall water splitting, the alkaline aqueous electrolyzer exhibits a low cell voltage of 1.80 V at the current density of 500 mA cm-2 with a remarkable durability of 100 h. The bifunctional NiFe LDH@Ni3N/NF electrocatalyst is very promising candidate for scale-up industrial implementation of hydrogen production due to its excellent catalysis activity and high stability.