NiS_x@MoS_2 heterostructure prepared by atomic layer deposition as high-performance hydrogen evolution reaction electrocatalysts in alkaline media

摘要

Developing low-cost and high-performance hydrogen evolution reaction (HER) electrocatalysts is essential for the development of hydrogen energy. While transition metal sulfides are reported as promising HER electrocatalysts, their performance still requires further improvement for practical application. In this work, we report a strategy to construct NiS_x@MoS_2 heterostructures with a well-defined interface structure by growing NiS_x nanoclusters on MoS_2 nanosheets through atomic layer deposition (ALO). NiS_x@MoS_2 heterostructures exhibit strongly enhanced HER activity with lower overpotential and faster reaction dynamic compared to MoS_2 and NiS_x single phases. The enhanced performance is attributed to improved adsorption of the reaction intermediates and the facilitated charge transfer process near the MoS_2/NiS_x interfaces. Besides high activity, NiS_x@MoS_2 heterostructures also exhibit high stability in alkaline media. The methodology and knowledge in this work can guide the rational design of high-performance electrocatalysts through hetero-interface engineering.