Highly active and durable self-standing WS2/graphene hybrid catalysts for the hydrogen evolution reaction

The development of three-dimensional (3D) efficient and earth-abundant electrocatalysts with good catalytic performance and long-term durability is desirable for the hydrogen evolution reaction (HER) in water splitting. Tungsten disulfide (WS2) has been long-pursued as a promising candidate, but the progress is slow, which is probably due to its poor electrical contact with the support and low density of active sites. Here we developed a highly active and stable WS2 catalyst for the HER by growing it into a 3D porous architecture on conducting graphene/Ni foam. The catalysts exhibit a similar to 0.1 V overpotential, accompanied by a large cathode current density (10 mA cm(-2) at -119 mV vs. reversible hydrogen electrode), a low Tafel slope of similar to 43 mV per decade and good stability. The HER performance of WS2 catalysts is greatly improved, and is comparable to that of the well-known catalysts (MoS2, CoSe2, CoS2, etc.), which benefits from the improved electrical conductivity of the WS2 catalysts by graphene and porous structures of the support. This work paves a new way to develop active and efficient WS2-based catalysts for hydrogen generation.