Facile synthesis of self support Fe doped Ni3S2 nanosheet arrays for high performance alkaline oxygen evolution

Abstract

• Fe doped Ni 3 S 2 /NF were prepared via a facile hydrothermal method. • The OER performance of Ni 3 S 2 /NF was significantly enhanced after Fe doping. • A small PDS for doped Ni 3 S 2 /NF of 0.31 eV can be obtained at the Fe site. Transition metal sulfides are one of the most efficient earth-abundant oxygen evolution reaction (OER) electrocatalysts. In the present study, Fe doped Ni 3 S 2 nanosheets have been directly grown on nickel foam via a facile hydrothermal process. The OER electrocatalytic activity of Fe-Ni 3 S 2 /NF can be enhanced by adjusting the addition amount of Fe. It requires an overpotential of 246 mV to afford a current density of 20 mA cm −2 and a Tafel slope of 66 mV dec −1 , significantly lower than that of Ni 3 S 2 /NF electrode. This catalyst is highly stable, showing a slight overpotential rise of 15.1 mV over continuous testing for 20 h. In addition, combine EIS measurement and density functional theory calculations, revealing that Fe doped Ni 3 S 2 /Ni electrodes have both high conductivity and excellent intrinsic activity, leading to a promising OER electrocatalytic activity.