Co-Motif-Engineered RuO₂ Nanosheets for Robust and Efficient Acidic Oxygen Evolution.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient acidic oxygen evolution reaction (OER) electrocatalysts are vital for water electrolysis.
• Ruthenium dioxide (RuO2) is a benchmark OER catalyst but suffers from instability via the lattice oxygen mechanism (LOM) in acidic media.
• Limited large-scale applicability of RuO2 necessitates strategies to enhance its acidic performance.

Purpose of the Study:

• To develop stable and efficient acidic OER electrocatalysts.
• To investigate the effect of cobalt (Co) doping on RuO2 morphology, electronic structure, and OER mechanism.
• To enhance the stability and performance of RuO2 for water electrolysis.

Main Methods:

• Synthesis of Co-doped RuO2 nanosheets with porous morphology using a molten salt method.
• Characterization of catalyst structure, surface area, and oxygen vacancies.
• Electrochemical evaluation of OER performance, including overpotential and stability tests.

Main Results:

• Co doping created porous RuO2 nanosheets with increased specific surface area and introduced oxygen vacancies.
• Co-O(V) motifs were formed, tuning the electronic configuration of Ru and promoting the adsorbate evolution mechanism (AEM) over LOM.
• The optimized Co0.108-RuO2 catalyst demonstrated a low overpotential (214 mV at 10 mA cm-2) and superior stability compared to undoped RuO2.

Conclusions:

• Cobalt doping effectively engineers RuO2 morphology and electronic structure, enhancing acidic OER performance.
• The shift to the AEM pathway and increased surface area are key to the improved catalytic activity and stability.
• This doping strategy offers a promising route for developing advanced electrocatalysts for efficient water electrolysis.