Amorphous High-entropy Phosphide Nanosheets With Multi-atom Catalytic Sites for Efficient Oxygen Evolution.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• The alkaline oxygen evolution reaction (OER) is crucial for energy conversion technologies.
• Balancing intermediate Gibbs free energies at active sites remains a key challenge in OER catalyst design.

Purpose of the Study:

• To synthesize and characterize a novel high-entropy metal-organic framework-derived phosphide/carbon composite (FeCoNiCuYP/C).
• To investigate the catalytic activity and stability of the FeCoNiCuYP/C composite for alkaline OER.
• To elucidate the structure-activity relationships and the role of specific metal sites in optimizing OER performance.

Main Methods:

• Electrodeposition synthesis of a high-entropy metal-organic framework template.
• Preparation of the high-entropy phosphide/carbon (FeCoNiCuYP/C) composite.
• Electrochemical characterization including overpotential and stability measurements.
• Theoretical calculations (DFT) and experimental measurements to analyze electronic structure and intermediate binding.

Main Results:

• The FeCoNiCuYP/C composite exhibits an amorphous structure with multiple active sites.
• Co/Ni and Fe atoms effectively tune the electronic structure and optimize intermediate binding strengths.
• Fe and Ni/Co sites preferentially stabilize HO* and HOO* intermediates, respectively, mitigating scaling relations.
• The catalyst achieves a low overpotential of 316 mV at 100 mA cm^-2 with excellent stability in alkaline media.

Conclusions:

• The developed FeCoNiCuYP/C electrocatalyst demonstrates superior performance for alkaline OER.
• High-entropy materials offer a promising strategy for designing efficient and stable electrocatalysts.
• This work provides a new avenue for advanced electrocatalytic applications.