Nanoflower-like FeVNi₃S_2-xas efficient electrocatalyst for alkaline oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient and cost-effective electrocatalysts are crucial for commercializing electrocatalytic water splitting.
• The oxygen evolution reaction (OER) is a critical bottleneck in water splitting due to its high overpotential and sluggish kinetics.
• Developing advanced catalysts is essential to overcome these limitations.

Purpose of the Study:

• To synthesize and characterize a novel electrocatalyst for the oxygen evolution reaction (OER).
• To investigate the effect of interface engineering and heteroatom doping on catalyst performance.
• To explore a new methodology for creating low-cost, highly active OER electrocatalysts.

Main Methods:

• Hydrothermal synthesis of iron and vanadium doped nickel sulfide on nickel foam.
• Hydrogen treatment to introduce sulfur defects.
• Electrochemical characterization including overpotential, Tafel slope, and long-term durability tests.
• In situ Raman spectroscopy to identify active catalytic species.

Main Results:

• The optimized FeVNi3S2-/NF catalyst exhibited an ultralow overpotential of 230 mV at 100 mA cm-2.
• The catalyst demonstrated rapid reaction kinetics with a Tafel slope of 46.6 mV dec-1.
• Excellent long-term durability was observed in 1 M KOH.
• Sulfur vacancies and synergistic heteroatom doping enhanced electrical conductivity and electrochemically active surface area.
• In situ Raman spectroscopy identified amorphous nickel oxyhydroxide (NiOOH) as the active OER species.

Conclusions:

• Interface engineering and heteroatom doping, combined with sulfur defects, significantly enhance OER performance.
• The developed FeVNi3S2-/NF catalyst offers a promising low-cost and highly active alternative to traditional transition metal catalysts.
• This work provides a valuable strategy for designing advanced electrocatalysts for water splitting applications.