Order-disorder engineering of RuO₂ nanosheets towards pH-universal oxygen evolution.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Ruthenium-based electrocatalysts show promise for water electrolysis in acidic media.
• Poor durability due to structural degradation and Ruthenium leaching limits their application.

Purpose of the Study:

• To develop a novel order-disorder structure optimization strategy for Ruthenium dioxide (RuO2) nanosheets.
• To enhance the durability and catalytic activity of RuO2 electrocatalysts for water oxidation, particularly in acidic environments.

Main Methods:

• Fabrication of RuO2 nanosheets with amorphous-crystalline boundaries on carbon cloth (a/c-RuO2/CC).
• Electrocatalytic performance testing for water oxidation.
• Durability assessment through electrochemical measurements.
• Computational simulations and experimental characterizations to understand structure-activity relationships.

Main Results:

• The a/c-RuO2/CC sample achieved a low overpotential (150 mV at 10 mA cm-2) and Tafel slope (47 mV dec-1).
• Significantly enhanced durability with suppressed Ruthenium dissolution compared to crystalline and amorphous counterparts.
• Structural optimization weakened Ru-O covalency, preventing active site leaching and boosting stability.
• Upshift of the d-band center improved the energy barrier for the potential-determining step, enhancing activity.

Conclusions:

• The order-disorder structure optimization strategy effectively enhances the stability and activity of RuO2 electrocatalysts for water oxidation.
• This approach offers a promising pathway to overcome durability limitations in acidic water electrolysis.
• The findings provide fundamental insights into designing robust and efficient electrocatalysts.