Phase Evolution on the Hydrogen Adsorption Kinetics of NiFe-Based Heterogeneous Catalysts for Efficient Water Electrolysis

Transition metal layered double hydroxides, especially nickel-iron layered double hydroxide (NiFe-LDH) shows significant advancement as efficient oxygen evolution reaction (OER) electrocatalyst but also plays a momentous role as a precursor for NiFe-based hydrogen evolution reaction (HER) catalysts. Herein, a simple strategy for developing Ni-Fe-derivative electrocatalysts via phase evolution of NiFe-LDH under controllable annealing temperatures in an argon atmosphere is reported. The optimized catalyst annealed at 340 C-o (denoted NiO/FeNi3) exhibits superior HER properties with an ultralow overpotential of 16 mV@10 mA cm(-2). Density functional theory simulation and in situ Raman analyses reveal that the excellent HER properties of the NiO/FeNi3 can be attributed to the strong electronic interaction at the interface of the metallic FeNi3 and semiconducting NiO, which optimizes the H2O and H adsorption energies for efficient HER and OER catalytic processes. This work will provide rational insights into the subsequent development of related HER electrocatalysts and other corresponding compounds via LDH-based precursors.

Automated summary

Transition metal layered double hydroxides, particularly nickel-iron layered double hydroxide (NiFe-LDH), play an important role as a precursor for efficient hydrogen evolution reaction (HER) catalysts. In this study, a simple strategy for developing Ni-Fe-derivative electrocatalysts via phase evolution of NiFe-LDH is reported. The optimized catalyst exhibits superior HER properties, and this can be attributed to the strong electronic interaction at the interface of the metallic FeNi3 and semiconducting NiO.