Ni3Se4/Fe(PO3)2/NF composites as high-efficiency electrocatalysts with a low overpotential for the oxygen evolution reaction

Abstract

The design of efficient, environment-friendly, stable, and low-cost oxygen evolution electrocatalysts is a technical difficulty in realizing the commercial application of water electrolysis. Herein, we developed a novel three-dimensional (3D) electrocatalyst to grow Ni₃Se₄/Fe(PO₃)₂ composites on nickel foam (NF) in a short time of 80 s by a simple electrodeposition method, which not only effectively prevents the agglomeration of Ni₃Se₄, but also reduces the size of Fe(PO₃)₂ particles from micron level to nanometer level, exposing more electroactive sites. Fe(PO₃)₂ with a low crystalline structure and crystalline Ni₃Se₄ can form a unique heterostructure to produce a strong electron coupling and synergistic effect for the oxygen evolution reaction (OER) in alkaline media, which effectively improves the intrinsic activity of Ni/FeOOH active sites. The Ni₃Se₄/Fe(PO₃)₂/NF composites as catalysts can achieve a low overpotential of 185 mV in alkaline media at a current density of 10 mA cm⁻² and a small Tafel slope of 30.4 mV dec⁻¹, exhibiting excellent OER catalytic activity and stability.