Electrically driven phosphorus dissolution from iron-nickel phosphate surfaces exposing highly active sites for...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Enhancing catalytic activity often involves optimizing surface composition to expose more active sites.
• Non-active components can hinder catalyst performance in reactions like oxygen evolution.

Purpose of the Study:

• To develop an electrically driven method for removing non-active phosphorus from iron-nickel phosphide.
• To optimize the surface of iron-nickel phosphide (P-O-NFF) for improved oxygen evolution reaction (OER) performance.

Main Methods:

• An electrically driven process was employed to selectively remove phosphorus (P) from iron-nickel phosphide.
• The surface composition of the catalyst was analyzed after the P removal process.

Main Results:

• The optimized P-O-NFF electrode demonstrated high OER catalytic activity with a low overpotential (217 mV at 10 mA cm⁻²).
• The electrode exhibited excellent stability, maintaining 100% voltage retention after 300 hours at 200 mA cm⁻².
• Electrically driven phosphorus dissolution led to amorphous Fe-Ni hydroxide/oxyhydroxide formation, increasing active site exposure.

Conclusions:

• The study presents an effective method for tuning catalyst surface composition to boost catalytic performance.
• This approach holds significant potential for advancing industrial water electrolysis technologies through enhanced catalyst design.