Hollow Nickel-Cobalt-Iron Phosphide Nanoprisms for Efficient Oxygen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrocatalysts are crucial for sustainable water electrolysis.
• The oxygen evolution reaction (OER) is a key bottleneck in water splitting.

Purpose of the Study:

• To synthesize a novel hollow trimetallic phosphide catalyst (NiCoFe-P) for enhanced OER performance.
• To investigate the structural and electronic properties influencing catalytic activity.

Main Methods:

• Synthesis of NiCoFe-P catalyst via a self-templated etching and gas-phase phosphorization process.
• Characterization using techniques like electron microscopy and spectroscopy.
• Electrochemical testing in alkaline electrolyte.
• Density functional theory (DFT) calculations and operando Raman spectroscopy.

Main Results:

• Hierarchical hollow architecture with uniform Ni, Co, Fe, and P distribution.
• Achieved low OER overpotential (274 mV at 10 mA cm⁻²), small Tafel slope (≈51 mV dec⁻¹).
• Demonstrated excellent durability (>100 h) and enhanced OER kinetics.

Conclusions:

• The hollow trimetallic phosphide catalyst exhibits superior OER activity and stability.
• Optimized Fe─O electronic coupling is key to facilitating oxygen intermediate formation and improving reaction kinetics.
• This catalyst represents a promising advancement for efficient water electrolysis.