Reconstructed CoFeP on nickel foam for highly efficient alkaline oxygen evolution.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) is crucial for energy conversion technologies.
• Hierarchical nanostructures offer high surface areas and enhanced catalytic activity.
• Cobalt and iron phosphides are promising precursors for OER electrocatalysts.

Purpose of the Study:

• To investigate the structural and electrochemical properties of a hierarchical CoFeP/NF electrocatalyst for OER.
• To understand the in-situ transformation mechanism of the catalyst during OER.
• To evaluate the catalytic performance and long-term stability of the CoFeP/NF catalyst in alkaline media.

Main Methods:

• Synthesis of hierarchical CoFeP/NF electrocatalyst.
• In-situ electrochemical characterization techniques (e.g., cyclic voltammetry, chronoamperometry).
• Post-mortem structural analysis (e.g., XRD, TEM, XPS).

Main Results:

• The CoFeP/NF electrocatalyst undergoes significant reconstruction during OER, forming active CoFe oxyhydroxide species.
• The catalyst exhibits a low overpotential of 178 mV at a current density of 10 mA cm^-2.
• Exceptional stability was demonstrated with continuous operation at 1 A cm^-2 for 500 hours in alkaline solution.

Conclusions:

• Hierarchical CoFeP/NF is an effective precursor for highly active and stable OER electrocatalysts.
• The in-situ formed CoFe oxyhydroxides are the key active species for OER.
• The catalyst shows great potential for applications in alkaline energy conversion systems.