Defect Engineering of a High-Entropy Metallic Glass Surface for High-Performance Overall Water Splitting at...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Platinum-based electrocatalysts are crucial for water electrolysis and hydrogen evolution reaction (HER).
• A significant challenge is balancing the cost-efficiency of these catalysts.
• High-entropy metallic glasses (HEMGs) offer potential for advanced catalytic applications.

Purpose of the Study:

• To develop a cost-effective platinum electrocatalyst with enhanced activity for water electrolysis.
• To investigate the role of defect engineering in high-entropy metallic glasses for catalysis.
• To achieve high performance in hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) under various conditions.

Main Methods:

• Fabrication of a nanoporous (FeCoNiB0.75)97Pt3 high-entropy metallic glass (HEMG) using a defect engineering strategy.
• Characterization of the HEMG's nanocrystalline surface structure, including lattice distortion and stacking faults.
• Electrocatalytic performance testing for HER and OER in alkaline, acidic, and neutral conditions.
• Computational modeling to understand the influence of defects on catalytic mechanisms.

Main Results:

• The defect-rich HEMG exhibited excellent electrocatalytic performance with ultralow overpotentials for HER (104 mV at 1000 mA cm⁻²) and OER (301 mV at 1000 mA cm⁻²) in alkaline media.
• The catalyst demonstrated high durability, exceeding 200 hours at 100 mA cm⁻².
• Low overpotentials were also observed for HER in acidic (81 mV at 1000 mA cm⁻²) and neutral (122 mV at 100 mA cm⁻²) conditions.
• Modeling indicated that lattice distortion and stacking faults optimize atomic configuration and electronic interactions, while nanoporous structures provide active sites.

Conclusions:

• Defect engineering in HEMGs is a viable strategy to create highly active and durable electrocatalysts with minimal precious metal content.
• The developed nanoporous Pt-decorated HEMG offers a cost-effective solution for efficient water electrolysis.
• This approach holds promise for the broader development of advanced alloy catalysts for energy applications.