Construction of Ni3S4-CeO2 nanocomposites for enhanced electrocatalytic alkaline oxygen evolution reactions

Abstract

Water electrolysis is an important way to achieve sustainable hydrogen production. However, the sluggish kinetics of the anodic oxygen evolution reaction (OER) brings about high energy consumption and low efficiency of the electrolysis process, which greatly limits its application. In this work, Ni₃S₄-CeO₂/NF electrocatalysts were prepared on nickel foam by secondary calcination and simple hydrothermal synthesis. The Ni₃S₄-CeO₂/NF catalysts exhibit outstanding electrochemical alkaline OER performance and durability. Among them, the optimized Ni₃S₄-CeO₂/NF catalyst requires only 110 mV overpotential to reach a current density of 10 mA cm⁻², with a Tafel slope of 42.3 mV dec⁻¹ in 1 M KOH. Furthermore, the current density of the Ni₃S₄-CeO₂/NF catalyst is stable over 20 hours, showing good catalytic stability. Studies have shown that the improved OER performance is due to CeO₂ accelerating charge transfer and adjusting the electronic structure of Ni₃S₄. This work provided a new strategy for constructing high activity alkaline OER electrocatalysts.