Hydrothermal Fabricated Ni3S4–Yb2O3 Heterojunction Electrocatalysts with Charge Redistribution for Efficient Alkaline Oxygen Evolution Reactions

Designing efficient and stable oxygen evolution reaction (OER) catalysts is of great significance for hydrogen production technology through the electrolysis of water. Nickel sulfide (NixSy) has garnered considerable attention as an OER electrocatalyst owing to its high electrical conductivity and distinctive structure. Herein, Ni3S4–Yb2O3 on nickel foam electrocatalysts was fabricated through a hydrothermal synthesis approach to optimize the performance of Ni3S4. The incorporation of Yb2O3 induced charge redistribution within Ni3S4, expanded the active surface area, and enhanced the availability of active sites. Consequently, the Ni3S4–Yb2O3/NF catalyst demonstrates exceptional electrocatalytic performance in 1 M KOH, attaining a current density of 10 mA cm–2 at a minimal overpotential of 148 mV, along with an ultralow Tafel slope of 47.3 mV dec–1. In addition, we have confirmed that another reason for the improved performance is that Yb2O3, as an electron donor, can effectively regulate the defects of the Ni atoms. This work offers a feasible strategy for developing highly effective OER electrocatalysts in alkaline media.