The study on the active origin of electrocatalytic water splitting using Ni-MoS2 as example

Two-dimensional layered sulfide (MoS2, VS2, WS2) has aroused intense scholarly interest, and its fascinating chemical properties and physical structure provide the possibility of further triggering the catalytic activity of the Ni. In this paper, we chose Ni and MoS2, which are both commonly used in electrocatalytic water splitting, to prepare the hybrid and then used it as a template to study the origin activity. With the method of experimental and theoretical reciprocal verification, it was discovered that the strong binding energy of Ni to MoS2 enables Ni to grow flat along the MoS2 surface to facilitate the Ni particles refinement and dispersion. Besides, the weakening of NiH bond demonstrated the subsequent recombination and release process of H in Ni-MoS2 catalyst is relatively easy. We hope this study may be extended to other two-dimensional transitional metal dichalcogenides based interface engineering to filtrate logical HER catalysts in alkaline media, and stimulate the rational design of the Ni-based materials as well as other transition metal catalysts.