Novel Ni₃S₂@NiOOH hybrid nanostructure supported on Ni foam as high-efficient electrocatalyst for hydrogen evolution reaction

Novel Ni₃S₂@NiOOH hybrid nanostructures have been synthesized using Ni foam (NF) as support and Ni source through a facile low-temperature sulfurization and following in situ electrochemical oxidation process. The structure and composition of the as-prepared samples were characterized by XRD, XPS and SEM. The uniform film composed of volcanic-like Ni₃S₂ nanostrucutres covered on the surface of Ni foam after 300 °C sulfurization in H₂S/N₂ for 1h. The similar film of Ni₃S₂@NiOOH hybrid nanostructure has been obtained after electrochemical treatment of Ni₃S₂/NF in 1.0 M KOH (called ET-Ni₃S₂/NF). The electrocatalytic performances of all the samples for hydrogen evolution reaction (HER) have been investigated. The obtained ET-Ni₃S₂/NF shows smaller onset potential and Tafel slope than Ni₃S₂/NF due to the formation of NiOOH nanoplates on the surface of NF. The synergistic effect between Ni₃S₂ and NiOOH may be responsible for the enhancement of the HER activity.