Engineering Amorphous/Crystalline Ru(OH)₃/CoFe-Layered Double Hydroxide for Hydrogen Evolution at 1000 mA cm^-2

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Industrial hydrogen production requires efficient, stable, and cost-effective electrocatalysts.
• The hydrogen evolution reaction (HER) is crucial for sustainable energy, particularly in water splitting.

Purpose of the Study:

• To develop a novel electrocatalyst for efficient hydrogen evolution reaction (HER) at high current densities.
• To investigate the stability and performance of the new catalyst in alkaline media for industrial applications.

Main Methods:

• Synthesis of a unique motif: crystalline cobalt-iron-layered hydroxide (CoFe-LDH) nanosheets enclosed by amorphous ruthenium hydroxide (a-Ru(OH)3).
• Electrochemical characterization of the a-Ru(OH)3/CoFe-LDH catalyst for HER performance.
• Long-term stability testing at a high current density of 1000 mA cm⁻² in 1.0 M KOH.

Main Results:

• The a-Ru(OH)3/CoFe-LDH catalyst achieved efficient hydrogen production at 1000 mA cm⁻² with a low overpotential of 178 mV.
• Demonstrated excellent long-term stability, with constant potential over 40 hours of continuous HER.
• Attributed performance to charge redistribution via oxygen vacancies, lowering charge-transfer resistance and promoting H2 formation/release.
• Water-splitting electrolyzer using a-Ru(OH)3/CoFe-LDH as anode and cathode showed stable hydrogen production and 100% faradic efficiency.

Conclusions:

• The a-Ru(OH)3/CoFe-LDH composite is a highly effective electrocatalyst for HER in alkaline media.
• Interface engineering strategy offers a promising pathway for designing practical electrocatalysts for industrial-scale water splitting.
• The catalyst's stability and efficiency at high current densities are significant advancements for green hydrogen production.