Ternary nickel cobalt iron layered double hydroxide nanosheet arrays are synthesized on nickel foam (NiCoFe-LDH/NF) and applied as an oxygen evolution reaction electrocatalyst. The oxidative etching and cation exchange caused by Fe-incorporating induce the change of morphology and the formation of Ni3+, thus increase the specific surface area and expose more active sites, finally greatly enhance the electrocatalytic OER performance. As a result, the Ni2CoFe0.5-LDH/NF electrode exhibits significantly enhanced oxygen evolution reaction performance with a small overpotential of 240 mV at the current density of 10 mAcm(-2), a small Tafel slope of 65 mV dec(-1) as well as an excellent durability in alkaline conditions for 72 h. Especially, the overpotential of Ni2CoFe0.5-LDH/NF is only 269 mV and 291 mV at 50 and 100 mA cm(-2), respectively. This work provides a good paradigm for the design and fabrication of ternary NiCoFe-based functional electrocatalysts, and demonstrates the great practical potential of the Ni2CoFe0.5-LDH/NF electrocatalyst in oxygen evolution reaction. (C) 2019 Elsevier Ltd. All rights reserved.