Hierarchical NiFeP microflowers directly grown on Ni foam for efficient electrocatalytic oxygen evolution

Abstract

Developing low-cost, highly efficient, and superior stable electrocatalysts for the oxygen evolution reaction (OER) is essential for upcoming renewable and clean energy systems. Here, 3D ternary nickel iron phosphide microflowers with a hierarchically porous morphology directly grown on Ni foam via a successive hydrothermal and phosphidation method are synthesized. Benefitting from their unique 3D hierarchical microflower-like structure and the strong electron interactions between Fe, Ni and P, the as-synthesized (Ni_xFe_1−x)₂P catalysts can effectively catalyze the OER with an overpotential of 219 mV at a current density of 20 mA cm⁻² in alkaline media, which is, to the best of our knowledge, the best among the reported non-noble metal-based catalysts.