Highly Efficient Hydrogen Evolution from Edge-Oriented WS_{2(1–<i>x</i>)}Se_2<i>x</i> Particles on Three-Dimensional Porous NiSe₂ Foam

The large consumption of natural fossil fuels and accompanying environmental problems are driving the exploration of cost-effective and robust catalysts for hydrogen evolution reaction (HER) in water splitting. Tungsten dichalcogenides (WS₂, WSe₂, etc.) are promising candidates for such purpose, but their HER performances are inherently limited by the sparse catalytic edge sites and poor electrical conductivity. Here we demonstrate a highly active and stable HER catalyst by integrating ternary tungsten sulfoselenide WS_{2(1–<i>x</i>)}Se_2<i>x</i> particles with a 3D porous metallic NiSe₂ foam, in which good electrical conductivity, good contact, large surface area, and high-density active edge sites are simultaneously obtained, thus contributing to outstanding catalytic performance: large cathode current density (−10 mA/cm² at −88 mV), low Tafel slope (46.7 mV/dec), large exchange current density (214.7 μA/cm²), and good stability, which is better than most reports on WS₂ and NiSe₂ catalysts. This work paves an interesting route for boosting HER efficiency of transition metal dichalcogenide catalysts.