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

Transition metal sulfides are one of the most efficient earth-abundant oxygen evolution reaction (OER) electrocatalysts. In the present study, Fe doped Ni3S2 nanosheets have been directly grown on nickel foam via a facile hydrothermal process. The OER electrocatalytic activity of Fe-Ni3S2/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 Ni3S2/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 Ni3S2/Ni electrodes have both high conductivity and excellent intrinsic activity, leading to a promising OER electrocatalytic activity.