Heterointerface enhanced NiFe LDH/V–Co4N electrocatalysts for the oxygen evolution reaction

Abstract

The development of high-performance and low-cost electrocatalysts for the oxygen evolution reaction (OER) is of great importance for renewable energy technologies. Herein, a highly efficient and stable self-supported electrocatalyst with V–Co₄N nanowires as the core and NiFe LDH nanosheet arrays as the shell is developed. The obtained NiFe LDH/V–Co₄N@NF shows strong electronic interaction at the heterointerface, which remarkably boosts its OER performance. It exhibits ultralow overpotentials of 203 and 240 mV at 10 and 100 mA cm⁻² in 1 M KOH solution, respectively, together with a much smaller Tafel slope of 26.0 mV dec⁻¹ and robust long-term durability. Structural characterization reveals that doping V contributes to the interfacial electron coupling between Co species and Fe species. Theoretical calculations confirm that the heterointerfaces reduce the free energy barriers of the rate-determining step. This study demonstrates the possibility of improving the OER performance of transition metal nitride catalysts through heterointerface engineering.