Zeolitic-imidazolate frameworks-derived Co3S4/NiS@Ni foam heterostructure as highly efficient electrocatalyst for oxygen evolution reaction

Transition metals sulfide-based nanomaterials have recently received significant attention as a promising cathode electrode for the oxygen evolution reaction (OER) due to their easily tunable electronic, chemical, and physical properties. However, the poor electrical conductivity of metal-sulfide materials impedes their practical application in energy devices. Herein, firstly nano-sized crystals of cobalt-based zeolitic-imidazolate framework (Co-ZIF) arrays were fabricated on nickel-form (NF) as the sacrificial template by a facile solution method to enhance the electrical conductivity of the electrocatalyst. Then, the Co3S4/[email protected] heterostructured arrays were synthesized by a simple hydrothermal route. The Co-ZIFs derived Co3S4 nanosheets are grown successfully on NiS nanorods during the hydrothermal sulfurization process. The bimetallic sulfide-based Co3S4/[email protected] electrocatalyst demonstrated a very low overpotential of 119 mV at 10 mA cm−2 for OER, which is much lower than that of mono-metal sulfide [email protected] (201 mV) and ruthenium-oxide (RuO2) on NF (440 mV) electrocatalysts. Furthermore, the Co3S4/[email protected] electrocatalyst showed high stability during cyclic voltammetry and chronoamperometry measurements. This research work offers an effective strategy for fabricating high-performance non-precious OER electrocatalysts.