Quasi-Parallel NiFe Layered Double Hydroxide Nanosheet Arrays for Large-Current-Density Oxygen Evolution Electrocatalysis

Designing advanced electrocatalysts for oxygen evolution at large current density (>500 mA cm(-2)) is critical to practical water splitting applications. Herein, a novel quasi-parallel NiFe layered double hydroxide (NiFe LDH) nanosheet arrays with pattern alignment on Ni foam was developed. The initial alpha-Ni(OH)(2) layer induced effective coprecipitation between Ni2+ and Fe3+ for the formation of LDH phase, guaranteeing the electronic pulling effect among metal cations and enhancing the interaction between active materials and substrate for excellent adhesion and electrical conductivity. Quasi-parallel NiFe LDH nanoarrays exhibited outstanding oxygen evolution activity with a small Tafel slope of 30.1 mV dec(-1) and overpotentials of 196, 255, and 284 mV at a current density of 10, 500, and 1000 mA cm(-2) in 1.0 m KOH solution, respectively, and high stability over 40 h at 750 mA cm(-2). This work presents a new strategy towards fabricating electrode materials with exceptional performance.