Highly Efficient Hydrogen Evolution from Edge-Oriented WS2(1-x)Se2x 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 WS2(1-x)Se2x 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.