Deep Eutectic Solvent-Assisted Corrosion Boosting Bulk FeCoNiCrMo High-Entropy Alloys as Highly Efficient Oxygen...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient catalysts are crucial for enhancing water electrolysis.
• High-entropy alloys (HEAs) exhibit superior catalytic performance due to their unique composition and structure.
• Electrocatalysis, particularly for the oxygen evolution reaction (OER), requires advanced materials.

Purpose of the Study:

• To develop a novel method for synthesizing high-activity catalysts for water electrolysis.
• To investigate the electrocatalytic properties of dealloyed HEAs for the oxygen evolution reaction (OER).
• To improve the efficiency and stability of OER catalysts.

Main Methods:

• Synthesis of a three-dimensional nanoporous structure using electrochemical one-step dealloying.
• Utilized an isoatomic FeNiCrMo high-entropy alloy (HEA) precursor.
• Employed a choline chloride-thiourea (ChCl-TU) deep eutectic solvent (DES).

Main Results:

• The dealloyed HEA consisted of face-centered cubic (FCC) and sigma (σ) phases.
• Preferential corrosion of the FCC phase led to an elemental imbalance and enhanced catalytic sites.
• Synergistic electron coupling in the nanoporous structure boosted OER activity.
• Achieved an overpotential of 370 mV at 40 mA cm⁻² with excellent stability.

Conclusions:

• Electrochemical dealloying in DES is an effective method to create advanced OER catalysts.
• The resulting nanoporous HEA exhibits significantly improved catalytic activity and stability.
• This approach offers a promising route for developing efficient electrocatalysts for water electrolysis.