Interfacial engineering of Ni₃S₂/NiFe-LDH heterojunctions: Modulated orbital hybridization and accelerated electron transfer for improved oxygen evolution kinetics

The heterostructure enhances the stability and activity of the catalyst. • The interfacial electron transfer and slight reconstruction synergistically enhance the catalyst performance. • d-p orbital hybridization enhances the metal synergy. • The formation of the heterojunction alters the rate-determining step of the reaction. This paper reports on a Ni 3 S 2 /NiFe-LDH heterostructure grown in-situ on a nickel foam substrate via a one-step hydrothermal method, and systematically evaluates its oxygen evolution reaction performance. This catalyst requires an overpotential of only 284 mV to reach a current density of 300 mA·cm −2 . Benefiting from the construction of the heterointerface, following 100 h galvanostatic electrolysis at 50 mA cm −2 , merely a 12 mV increase in overpotential was detected at 300 mA cm −2 in post-stability LSV tests. In-depth mechanistic analysis reveals that the introduction of Ni 3 S 2 triggers interfacial electronic reconstruction. Spin polarization and orbital hybridization collectively optimize the density of states of NiFe-LDH, accelerate charge transfer, and enhances its intrinsic catalytic kinetics. This work not only develops a high-performance oxygen evolution catalyst, but also provides a rational strategy for modulating electronic structures via heterointerface engineering to enhance electrocatalytic performance. Download: Download high-res image (328KB) Download: Download full-size image