Fe-Doping-Accelerated Deep Reconstruction of KCoF₃ for Enhanced Alkaline Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient catalysts for the oxygen evolution reaction (OER) is critical for energy conversion technologies.
• Catalyst deep reconstruction into active oxyhydroxides presents a significant challenge.

Purpose of the Study:

• To design and synthesize a catalyst capable of self-reconstruction for enhanced alkaline OER.
• To investigate the role of Fe doping in catalyst reconstruction and OER mechanism.

Main Methods:

• Rational synthesis of KCo1-xFexF3 perovskite materials.
• Electrochemical characterization of OER performance in alkaline media.
• In situ Raman spectroscopy to study catalyst reconstruction.

Main Results:

• KCo1-xFexF3 undergoes self-reconstruction via ion leaching to form amorphous (Co, Fe)OOH active layers.
• Fe incorporation enhances bond dissociation, promotes deep reconstruction, and switches the OER mechanism to lattice oxygen-mediated mechanism (LOM).
• Reconstructed KCo0.7Fe0.3F3 exhibits a low overpotential (257 mV at 10 mA cm-2) and excellent stability (>100 h at 100 mA cm-2).

Conclusions:

• A rational strategy for deep catalyst reconstruction is demonstrated.
• Fe-doped KCoF3 perovskites serve as efficient precursors for highly active and stable OER electrocatalysts.
• The findings provide fundamental insights into enhancing OER catalytic activity through controlled reconstruction.