NiFe2O4 spinel supported CoCr-LDH nanosheets for efficient oxygen evolution catalysis

Abstract

Developing high-performance non-noble metal-based electrocatalysts for oxygen evolution reaction (OER) is important for hydrogen production from water electrolysis. In this work, a unique method to simultaneously improve the catalytic activity and stability of NiFe₂O₄ spinel is carried out through heterogeneous nucleation sintering. So that the resultant corrugated CoCr-LDH nanosheets can strongly combine onto NiFe₂O₄ surfaces to form finned structures, which enhances the surface area and OER catalytic performance of the resultant catalysts. The optimized NiFe₂O₄@CoCr-LDH/NF exhibits excellent OER performance with a low overpotential of 193 mV at 10 mA cm^-2 and a low Tafel slope (27.5 mV dec^-1), and outstanding stability performance. Furthermore, the NiFe₂O₄@CoCr-LDH/NF also displays attractive bifunctional catalytic activities, which achieves an ultra-low voltage for overall water splitting of 1.546 V at 10 mA cm^-2. These results indicate that NiFe₂O₄@CoCr-LDH/NF is a promising low-cost catalyst for hydrogen production through water splitting.