The design and synthesis of Fe doped flower-like NiS/NiS2 catalyst with enhanced oxygen evolution reaction

Abstract

• A cheap Fe doped flower-like NiS/NiS 2 catalyst for OER is designed and synthesized. • Fe doping regulates the phase composition, heterogeneous interface and OER activity. • Fe-NiS/NiS 2 catalyst demonstrates excellent OER performance, exceeding RuO 2 and NiS 2 . Exploring low-cost and high-activity transition metal-based electrocatalysts for oxygen evolution reaction (OER) is critical toward mass hydrogen generation by water splitting. Herein, a cheap Fe element doped flower-like nickel sulfides catalyst (Fe-NiS/NiS 2 ) is designed and synthesized through facile electrostatic adsorption and sulfuration methods. It is investigated that the Fe doping effectively induces the lattice contraction of nickel sulfides and regulates the phase composition and heterogeneous interfaces, thus enabling high intrinsic OER activity. The Fe-NiS/NiS 2 catalyst shows a high electrochemically active surface area of 150 cm 2 , a small overpotential of 361 mV at 100 mA cm −2 and a low Tafel slope of 61.5 mV dec -1 . Furthermore, the Fe-NiS/NiS 2 exhibits a very excellent structure and performance stability without current attenuation for 24 h at 1.50 V versus reversible hydrogen electrode. This work provides an important insight for the exploitation of low-cost and high-performance OER catalysts with cheap Fe element doping metal sulfides.