Iron-Doped\nNickel Phosphide Nanosheet Arrays: An Efficient Bifunctional Electrocatalyst\nfor Water Splitting

Abstract

Exploring\nefficient and earth-abundant electrocatalysts for water splitting\nis crucial for various renewable energy technologies. In this work,\niron (Fe)-doped nickel phosphide (Ni₂P) nanosheet arrays\nsupported on nickel foam (Ni_1.85Fe_0.15P NSAs/NF)\nare fabricated through a facile hydrothermal method, followed by phosphorization.\nThe electrochemical analysis demonstrates that the Ni_1.85Fe_0.15P NSAs/NF electrode possesses high electrocatalytic\nactivity for water splitting. In 1.0 M KOH, the Ni_1.85Fe_0.15P NSAs/NF electrode only needs overpotentials of 106 mV\nat 10 mA cm^–2 and 270 mV at 20 mA cm^–2 to drive the hydrogen evolution reaction (HER) and oxygen evolution\nreaction (OER), respectively. Furthermore, the assembled two-electrode\n(Ni_1.85Fe_0.15P NSAs/NF∥Ni_1.85Fe_0.15P NSAs/NF) alkaline water electrolyzer can produce\na current density of 10 mA cm^–2 at 1.61 V. Remarkably,\nit can maintain stable electrolysis over 20 h. Thus, this work undoubtedly\noffers a promising electrocatalyst for water splitting.