Controllable synthesis of Ni3S2@MOOH/NF (M = Fe, Ni, Cu, Mn and Co) hybrid structure for the efficient hydrogen evolution reaction.

The design and synthesis of hybrid core-shell catalysts is of great significance for obtaining an excellent performance of hydrogen evolution reaction (HER). However, it remains a challenge to explore the exact active sites and research the catalytic mechanism for HER. Here, a series of Ni3S2@MOOH/NF (M = Fe, Ni, Cu, Mn and Co) hybrid structures is firstly in-site grown on Ni foam by the typical hydrothermal and electrodeposition methods. The Ni3S2@NiOOH/NF catalyst with a core-shell structure exhibits a relatively low overpotential of 79 mV for HER at a current density of 10 mA cm-2, which is one of the best catalytic activities reported so far. Moreover, it also shows good stability in the long-term durability test. Various spectral analysis and density functional theory calculations demonstrate that NiOOH is favorable for the adsorption of water molecules, and the S atom at the interface between Ni3S2 and NiOOH is favorable for the adsorption of H intermediates, which strongly accelerates the HER process in alkaline solution. This work provides a general strategy for the synthesis of electrocatalytic materials, which can be used for efficient electrocatalytic water splitting reactions.