Manganese, iron co-doped Ni2P nanoflowers as a powerful electrocatalyst for oxygen evolution reaction

Abstract

MnFe-Ni 2 P/NF is synthesized by a simple hydrothermal and subsequent phosphorylation reaction. The prepared material has excellent OER activity with an overpotential of 220 mV at a current density of 10 mA cm −2 . • Trimetallic transition metal phosphide nanoflowers are in-situ synthesized on Ni foam. • The unique flower-like structure provides more active sites for the OER reaction. • MnFe-Ni 2 P/NF shows high catalytic stability for OER in alkaline media. • MnFe-Ni 2 P/NF shows higher catalytic activity than that of bimetallic phosphides. The development of abundant, high-performance electrocatalysts for oxygen evolution reactions (OER) is an ongoing challenge to renewable energy. Herein, we rationally synthesized a manganese (Mn) and iron (Fe) doped Ni 2 P nanosheet (MnFe-Ni 2 P) as a highly efficient electrocatalyst for OER in alkaline solution by a simple hydrothermal method and phosphorylation. The bimetal-doped phosphide nanosheets are directly grown on the conductive nickel foam (NF) to form a 3D structure which facilitates to expose active sites as much as possible. Due to the electron interaction between the Mn, Fe and Ni, which contributes to ion diffusion and gas release, trimetallic MnFe-Ni 2 P/NF delivers an extremely low overpotential of 220 mV at 10 mA cm −2 and a small Tafel slope of 53 mV dec −1 in alkaline electrolyte towards OER. Furthermore, the excellent stability of MnFe-Ni 2 P/NF lasts for at least 24 h at a high current density of 50 mA cm −2 without much deviation. We demonstrate that the trimetallic MnFe-Ni 2 P/NF benefits from the doping of Mn, Fe elements and the unique flower-like structure, exhibits more effective electrocatalytic activity compare to conventional noble metal catalysts and Ni 2 P series materials.