Phosphorus-Modified High-Entropy Layered Double Hydroxide for Enhanced Electrocatalytic Oxygen Evolution via d-Band...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing cost-effective, high-performance electrocatalysts for the oxygen evolution reaction (OER) is critical for water splitting.
• High-entropy layered double hydroxides (HE-LDHs) offer potential due to multimetal synergy but face limitations in electronic and surface properties.

Purpose of the Study:

• To enhance OER performance and stability of HE-LDHs by incorporating phosphorus (P) atoms.
• To optimize oxygen intermediate adsorption and reduce the energy barrier for the rate-determining step in OER.
• To develop a novel strategy for designing efficient water-splitting catalysts.

Main Methods:

• Synthesis of P-modified FeNiCoCuZn LDH (P-FeNiCoCuZn LDH) using hydrothermal and low-temperature phosphatization.
• Theoretical and experimental investigations to understand the role of phosphorus.
• In situ Raman spectroscopy to identify active species during OER.

Main Results:

• P-FeNiCoCuZn LDH exhibits phosphate anion intercalation and surface metal phosphides.
• Phosphate anions improve conductivity and stability; surface P atoms optimize electronic structure, particularly for Ni and Fe sites.
• Achieved a low overpotential of 290 mV at 100 mA cm⁻² and 100 h stability in 1 M KOH.
• Identified highly active Ni(Fe)OOH species during OER via in situ Raman spectroscopy.

Conclusions:

• In situ heteroatom modification with phosphorus is a viable strategy for designing efficient HE-LDH electrocatalysts.
• This approach significantly boosts OER activity and stability, advancing the application of high-entropy materials in electrocatalysis.
• The study provides insights into optimizing catalyst design for water-splitting applications.