Selenium-activated monolithic FeNi layered double hydroxide electrodes: binder-free, self-supported architectures for...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts is crucial for alkaline water electrolysis.
• Earth-abundant, durable, and scalable catalysts are needed for industrial applications.

Purpose of the Study:

• To introduce a novel Se-activated FeNi layered double hydroxide (Se-FeNi-LDH) electrode.
• To evaluate its performance as an oxygen evolution reaction (OER) electrocatalyst in alkaline media.

Main Methods:

• Fabrication of a monolithic, binder-free Se-FeNi-LDH electrode on an FeNi alloy substrate.
• Electrochemical characterization including overpotential, Tafel slope, and stability tests.
• Performance evaluation in a practical alkaline water electrolyzer.

Main Results:

• The optimized FeNi-LDH1-Se0.5 electrode exhibited low overpotentials (240 mV at 10 mA cm⁻²) and a Tafel slope of 37 mV dec⁻¹.
• Demonstrated stable operation for 120 hours at 100 mA cm⁻².
• Achieved a cell voltage of 1.56 V at 10 mA cm⁻² in a practical electrolyzer.

Conclusions:

• Selenium activation enhances the electronic structure and kinetics of FeNi-LDH, improving OER performance.
• The binder-free monolithic architecture ensures efficient transport and mechanical robustness.
• This strategy offers a scalable and high-performance solution for alkaline water electrolysis.