Core-Shell Prussian Blue Analogs with Compositional Heterogeneity and Open Cages for Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Prussian blue analogs (PBAs) are versatile materials with tunable properties.
• Developing PBAs with controlled composition and structure is crucial for advanced applications.
• Oxygen evolution reaction (OER) catalysis requires efficient and stable electrocatalysts.

Purpose of the Study:

• To develop a novel synthesis strategy for Fe-Co bimetallic PBAs.
• To create PBAs with heterogeneous composition distribution and open cage architecture.
• To evaluate the catalytic performance of these novel PBAs for the oxygen evolution reaction.

Main Methods:

• Synthesis of Fe-Co PBAs using a reduction-cation exchange (RCE) strategy.
• Characterization of PBA composition, structure, and morphology using electron tomography and energy-dispersive X-ray spectroscopy.
• Electrocatalytic evaluation of PBAs for the oxygen evolution reaction (OER) under various conditions.

Main Results:

• Successful synthesis of Fe-Co PBAs with a core-shell structure (Fe-rich shell, Co-rich core) and open cage architecture.
• Demonstrated heterogeneous element distribution and unique structural properties.
• Achieved superior OER activity (271 mV at 10 mA cm⁻²) and long-term stability (≈5.3% potential increase over 24 h).
• High specific surface area (576.2 m² g⁻¹) contributed to enhanced catalytic performance.

Conclusions:

• The RCE strategy enables the synthesis of PBAs with compositional and structural multiplicity.
• The synthesized Fe-Co PBAs exhibit excellent OER performance due to their unique properties.
• This work provides insights for designing advanced PBAs for practical catalytic applications.