Incorporating iron in nickel cobalt layered double hydroxide nanosheet arrays as efficient oxygen evolution electrocatalyst

Abstract

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 mA cm−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.