NiFe double hydroxide coated on sulfur-modified NiMoO4 nanorods as core–shell structured catalysts for the oxygen evolution reaction

Abstract

The rational development and utilization of inexpensive, highly efficient and stable electrocatalysts are of practical importance for the oxygen evolution reaction (OER) in the process of splitting water. In this paper, a layered core–shell structure of dispersed NiFe layered double hydroxide on S-modified NiMoO₄ nanorods (NiFe LDH@S-NiMoO₄) grown on nickel foam (NF) was designed by a two-step hydrothermal and electrodeposition method. The constructed electrocatalyst possesses large specific surface area, excellent OER catalytic activity and durability. In 1 M KOH solution, only an overpotential of 277 mV is required at a current density of 100 mA cm⁻², and the corresponding Tafel slope is 78 mV dec⁻¹, which verifies the good OER performance. After 3000 cycles of cyclic voltammetry and 70 hours of chronopotentiometry testing, there was no obvious change in overpotential, showing superior durability. Compared with other noble metal OER electrocatalyst materials, NiFe LDH@S-NiMoO₄ exhibits more excellent OER performance, providing a new choice for OER catalysts.