Colloidal Synthesis of NiWSe Nanosheets for Efficient Electrocatalytic Hydrogen Evolution Reaction in Alkaline Media

Abstract Searching for efficient, low‐cost, and durable electrocatalysts toward the hydrogen evolution reaction (HER) is extremely urgent for future energy conversion systems. Herein, the colloidal synthesis of 2D tungsten‐doped nickel selenide nanosheets by using Ni(acac) 2 (acac=aceylacetonate), [W(CO) 6 ], and selenium powder as precursors in oleylamine is reported. The introduction of tungsten is essential for the formation of 2D nanosheets. As a result, by taking the advantage of the unique layered structure and strong synergistic electronic effect between nickel, tungsten, and selenium, the as‐synthesized Ni 0.54 W 0.26 Se nanosheets exhibit superior catalytic activity toward the HER in alkaline media, with an overpotential of 162 mV ( η 10 ), which is much lower than those of NiSe 2 ( η 10 =330 mV) and WSe 2 ( η 10 =378 mV), and higher than that of most previously reported selenide‐based electrocatalysts.