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.