One-step synthesis of nanowoven ball-like NiS-WS2 for high-efficiency hydrogen evolution

Exploring transition metal sulfide electrocatalysts with high-efficiency for hydrogen evolution reaction (HER) is essential to produce H2 fuel through water splitting. Herein, novel nickel tungsten sulfide heterojunction (NiS-WS2) with a nanowoven ball-like structure were directed synthetized by a facile hydrothermal method. The hierarchical NiS-WS2 exhibited excellent HER activity with a relatively small overpotential of 142 mV and 137 mV at 10 mA/cm2 in 0.5 mol/L H2SO4 and 1 mol/L KOH, which is much better than that of single NiS and WS2. The impressive performance of NiS-WS2 heterojunction is owed to the collective synergy of special morphological and more exposed active sites between the crystal interfacial of NiS and WS2. In addition, the hierarchical NiS-WS2 can facilitate the transport of charge/mass by optimized electronic structure, which further improves the HER activity of electrocatalysts. These outcomes provide a simple method to prospect towards the design and application of heterostructures as efficient electrocatalysts, shedding some light on the development of functional materials in energy chemistry.