Enriched Fe Doped on Amorphous Shell Enable Crystalline@Amorphous Core-Shell Nanorod Highly Efficient Electrochemical...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrocatalysts are crucial for clean energy technologies like water splitting.
• The oxygen evolution reaction (OER) is a key bottleneck due to its sluggish kinetics.
• Designing electrocatalysts with abundant active sites is essential for improved performance.

Purpose of the Study:

• To develop a cost-effective and efficient electrocatalyst for the oxygen evolution reaction (OER).
• To investigate the structure-property relationships of crystalline/amorphous heterostructures for OER.
• To explore the role of Fe doping in Ni-Co phosphide for enhanced catalytic activity.

Main Methods:

• Synthesis of Fe-doped Ni-Co phosphide (Fe-NiCoHPi) with a cauliflower-like, crystalline@amorphous core-shell nanorod structure.
• Characterization of the catalyst's morphology, composition, and electronic structure.
• Density functional theory (DFT) calculations to understand the mechanism of enhanced activity at the core-shell interface.

Main Results:

• The Fe-NiCoHPi catalyst exhibits a unique crystalline@amorphous core-shell nanorod structure with Fe enrichment in the amorphous shell.
• DFT calculations reveal strong electronic interactions at the interface, leading to balanced binding energies for OER intermediates.
• The catalyst demonstrates remarkable OER activity with low overpotentials (206 mV at 15 mA cm⁻²) and excellent durability (>90 h).

Conclusions:

• The crystalline@amorphous heterostructure design effectively creates abundant active sites and enhances OER performance.
• Fe doping and the core-shell interface play critical roles in optimizing the electronic properties for catalysis.
• This work presents a promising strategy for designing advanced electrocatalysts for sustainable energy devices, though challenges at high currents remain.