It is of great significance to design an efficient and low-cost oxygen evolution reaction (OER) electrocatalyst for water splitting to utilize hydrogen energy. In this work, three-dimensional flower-like bimetallic Ni–Fe selenide electrocatalysts were successfully fabricated on nickel foam by a facile one-step chemical bath method. Benefiting from the bimetal synergistic effect of Ni/Fe bimetal and a large electrochemically active surface area provided by the unique three-dimensional flower-like structure and improved conductivity of metal selenides, the as-prepared Ni0.2Fe0.8Se–Se/NF exhibits good OER activity, that is, a small overpotential of 200 mV at 10 mA cm–2, a low Tafel slope of 57.7 mV dec–1, and high stability of 26 h in 1.0 M KOH. The work may provide a new idea to fabricate other transition-metal-based catalysts for efficient water splitting.

The development of efficient and low-cost transition-metal electrocatalysts is of great significance for hydrogen production from water splitting. Herein, we synthesized three-dimensional strawlike MoSe2-NiSe composed of microrods on nickel foam (NF) by a one-step hydrothermal reaction. The as-prepared MoSe2-NiSe/NF exhibited effective hydrogen evolution reaction (HER) activity (low overpotential of 79 mV at 10 mA cm–2 and stability of 21 h in 1 M KOH), benefiting from the large electrochemically active area provided by strawlike structures, proper Se content, and synergistic effect of active phases. The enhanced oxygen evolution reaction (OER) activity (the low overpotential of 217 mV at 10 mA cm–2 and maintaining stability for 47 h in 1 M KOH) was further observed for Fe-doped MoSe2-NiSe/NF (MoSe2-NiFeSe/NF) prepared by facile soaking, which can be mainly ascribed to optimized active phases formed on the OER process after Fe doping. The two-electrode system (MoSe2-NiSe/NF||MoSe2-NiFeSe/NF) requires a low cell voltage of 1.54 V to obtain a current density of 10 mA cm–2 in 1 M KOH, which provides an interesting idea for constructing an effective overall water splitting system.

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