Dynamically Reconstructed Fe-CoOOH Semi-Crystalline Electrocatalyst for Efficient Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) is crucial for water electrolysis.
• Current OER catalysts face challenges in activity and long-term stability.

Purpose of the Study:

• To synthesize a highly active and ultra-stable Fe-CoOOH electrocatalyst for the oxygen evolution reaction.
• To investigate the surface reconstruction and doping mechanisms influencing catalyst performance.

Main Methods:

• In situ solution combustion synthesis assisted by galvanic replacement reaction.
• Electrochemical reconstruction of a CoFeOₓ pre-catalyst.
• In/ex situ electrochemical analysis and physicochemical characterizations.
• Theoretical calculations (DFT) to understand doping effects.

Main Results:

• The synthesized Fe-CoOOH exhibits a semi-crystalline nanosheet structure with short-range ordering.
• Achieved low overpotentials of 271 mV at 500 mA cm⁻² and 291 mV at 1000 mA cm⁻².
• Demonstrated remarkable stability, maintaining performance at 1000 mA cm⁻² for over 700 hours.
• Fe doping was confirmed to facilitate surface reconstruction and enhance OER activity and stability.

Conclusions:

• Fe-CoOOH is a highly active and stable electrocatalyst for the oxygen evolution reaction.
• Surface reconstruction and Fe doping are key factors for improved OER performance.
• This study provides valuable insights into catalyst design for efficient water electrolysis.