Self-supported Ni–Co–Fe ternary metal phosphide for highly efficient oxygen evolution reaction: DFT and experimental insights

Advancing the development of economical, high-performance, and durable non-precious metal electrocatalysts for oxygen evolution reaction (OER) holds critical significance. This study presents a self-supporting ternary metal phosphide (NiCoFe–P/NF) electrode developed by direct phosphating metal-organic frameworks (MOFs) precursor. Benefiting from a three-dimensional hierarchical porous structure, optimized electronic configuration, high electrical conductivity, and synergistic effect of multiple elements, the synthesized NiCoFe–P/NF electrocatalyst exhibits exceptional catalytic performance compared to the monometallic or bimetallic phosphides, achieving a low overpotential of 209 mV and a Tafel slope of 29 mV dec−1 at 10 mA cm−2 in 1 M KOH solution. In addition, the prepared catalyst exhibits superior stability and durability, as evidenced by its well-preserved morphology after 48 h of stability test. Furthermore, at a high current density of 100 mA cm−2, the long-term efficiency remains >90% even after 96 h. Density functional theory (DFT) calculations reveal that the high catalytic performance of the NiCoFe–P/NF catalyst is ascribed to modified electronic states and lower adsorption energy to the related species. This study not only presents the synthesis of extremely stable and active OER catalysts but also offers a novel and practical method for the development of new catalysts.