Nanostructured NiCo2S4@NiCo2O4-reduced graphene oxide as an efficient hydrogen evolution electrocatalyst in alkaline electrolyte.

Metal-organic frameworks (MOFs), serving as precursors or templated to construct nanomaterials, which have gained great attentions in the field of electrocatalysis. However, their applications still remain some challenges due to poor conductivity and easy agglomeration. In this work, the MOFs-derived NiCo2S4@NiCo2O4 deposited on reduced Graphene Oxide (rGO) surface is designed by using a facile hydrothermal procedure. Attribute to the enlarged active surface area of the nanostructure and the strong synergistic effect between NiCo2S4 and NiCo2O4, as well as the excellent conductivity of rGO. The NiCo2S4@NiCo2O4-rGO catalyst displays ultrahigh hydrogen evolution reaction (HER) property and excellent stability, only need an overpotential of η10 = 95 mV to attain 10 mA cm-2 and deliver a small Tafel slope of b = 52 mV dec-1 in 1 M KOH. This work can provide a window to construct and develop new noble metal-free HER catalysts base on Ni-MOFs served as precursors.