Enhancing the oxygen evolution reaction: Synergistic interaction of nickel–cobalt selenide and iron oxyhydroxide electrocatalysts

The development of stable and efficient bifunctional catalysts for total water splitting is crucial for renewable energy sources. The focus on noble-metal–free electrocatalysts with enhanced active sites is equally crucial. Meanwhile, studies related to heterostructure-based water electrolysis catalysts have also been reported. While transition metal compounds, such as selenides, have distinct characteristics, their stability and electroactivity still need improvement. This study aims to reduce overpotential by utilizing both the crystalline and amorphous nature of the designed electrocatalyst. The electrocatalyst is synthesized by electrodepositing a nickel–cobalt selenide (NCS) onto nickel foam, followed by chemical bath deposition to form iron oxyhydroxide. The resulting electrocatalyst exhibits a low overpotential of 222.5 mV at a high current density of 50 mA/cm², outperforming pristine NCS by 82.5 mV. Furthermore, the electrocatalyst demonstrates stability for 71.5 h under a constant current density of 50 mA/cm², with minimal changes in morphology and a consistent potential. This study presents a straightforward and effective method for preparing high-performance electrocatalysts and highlights the significance of interface engineering in utilizing transition metal chalcogenides that enhance the catalytic activity for energy production.