The development of bifunctional electrocatalysts that demonstrate both high efficiency and robust stability for overall water splitting remains a significant challenge in advancing sustainable hydrogen production. In this study, a NiCrFe-layered double hydroxide (LDH) nanostructure was fabricated on nickel foam and subsequently subjected to partial or complete sulfidation using three different sulfidating agents (Na 2 S, C 2 H 5 NS thioacetamide, and CH 4 N 2 S thiourea). A variety of detailed characterization methods were employed to analyze the catalysts, including scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). Their electrocatalytic performance was then systematically assessed. Among them, NiFeCr-LDH-NF-CH₄N₂S2 (fully sulfidated with CH₄N₂S) exhibited the most remarkable activity, requiring a low overpotential to achieve 10 mA cm −2 for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), along with the smallest Tafel slope, signifying rapid reaction kinetics. Electrochemical impedance spectroscopy revealed its low charge-transfer resistance, while cyclic voltammetry and stability tests confirmed excellent durability and a large electrochemical surface area. Furthermore, CrNiFe-LDH-NF-ThU2 demonstrated the highest mass activity compared to benchmark catalysts (Pt and IrO₂/RuO₂), underscoring its efficiency. Highlights • NiFeCr-LDH-NF-CH₄N₂S₂ shows exceptional bifunctional activity for both OER and HER. • Requires low overpotential at 100 mA cm −2 with the smallest Tafel slope. • Exhibits low charge-transfer resistance, large ECSA, and superior durability. • LTH-NF-ThU₂ surpasses Pt and IrO₂/RuO₂ in mass activity. • Promising candidate for practical water electrolysis and sustainable energy applications.
Shadbad et al. (Sun,) studied this question.