Interface engineering of NiS@MoS2 core-shell microspheres as an efficient catalyst for hydrogen evolution reaction in both acidic and alkaline medium

Electrochemical splitting of water is one of the most reliable and effective ways for the sustainable production of pure hydrogen on a large scale, while the core of this technology lies in the development of highly active non-noble-metal-based electrocatalysts to lower the large dynamic overpotentials of electrode materials. Here, an interface engineering strategy is demonstrated to construct an efficient and stable catalyst based on NiS@MoS 2 core-shell hierarchical microspheres for the hydrogen evolution reactions (HER). The ultrathin MoS 2 nanosheets in-situ grow on the surface of NiS hierarchical micro-sized spheres constructed by porous nanoplates, endowing the composites with rich interfaces, well-exposed electroactive edges, high structural porosity and fast transport channels. These advantages are favorable for the improvement of catalytic sites and the transport of catalysis-relevant species. More importantly, the intimate contact between MoS 2 nanosheets and NiS nanoplates synergistically favors the chemical sorption of hydrogen intermediates, thereby reducing the reaction barrier and accelerating the HER catalytic process. As a result, the optimized NiS@MoS 2 catalyst manifests impressive HER activity and durability, with a low overpotential of 208 mV in 0.5 M H 2 SO 4 and 146 mV in 1.0 M KOH at 10 mA cm −2 , respectively. This work not only provides an effective way to construct core-shell hierarchical microspheres but also a multiscale strategy to regulate the electronic structure of heterostructured materials for energy-related applications. • The NiS@MoS 2 core-shell microspheres were synthesized via in-situ growth of MoS 2 on NiS nanoplates. • The NiS@MoS 2 catalyst possessed well-exposed electroactive sites, high structural porosity and fast transport channels. • The strong interfacial interactions between NiS nanoplates and MoS 2 nanosheets lowered the sorption energy of H∗. • The NiS@MoS 2 catalyst manifested excellent HER activity and durability both in acidic and alkaline solution.