Metal - organic frameworks derived Ni₅P₄/NC@CoFeP/NC composites for highly efficient oxygen evolution reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Phosphide catalysts are efficient for oxygen evolution reaction (OER) but suffer from poor electrical conductivity.
• Designing advanced structures is crucial to improve conductivity and OER performance.

Purpose of the Study:

• To develop a novel composite electrocatalyst for enhanced OER performance.
• To address the conductivity limitations of non-precious metal phosphides.

Main Methods:

• Fabrication of a Ni5P4/N-doped carbon@CoFeP/N-doped carbon (Ni5P4/NC@CoFeP/NC) composite.
• Utilizing Ni-MOF and CoFe-Prussian blue analog MOF as precursors.
• Characterization using X-ray Photoelectron Spectroscopy (XPS).

Main Results:

• The Ni5P4/NC@CoFeP/NC catalyst exhibited excellent OER performance.
• Achieved low overpotentials of 260 mV (10 mA·cm⁻²) and 303 mV (100 mA·cm⁻²).
• Demonstrated an ultra-low Tafel slope of 31.1 mV·dec⁻¹ and superior stability in 1 M KOH.

Conclusions:

• The composite structure enhances conductivity and electrochemical active surface area.
• Optimized chemical composition facilitates transition metal oxidation and OH⁻ chemisorption, accelerating OER kinetics.
• Presents a promising strategy for designing transition metal phosphide/carbon composites for OER applications.