Orientation-modulated oxygen evolution reaction in epitaxial SrRuO₃ films

Area of Science:

• Materials Science
• Electrochemistry
• Surface Science

Background:

• Strontium ruthenium oxide (SrRuO3) is a material with interesting electronic and catalytic properties.
• Understanding the relationship between film properties and catalytic activity is crucial for developing advanced materials.
• The oxygen evolution reaction (OER) is a key process in many electrochemical applications, such as water splitting.

Purpose of the Study:

• To investigate the local oxygen evolution reaction (OER) performance of SrRuO3 films grown on SrTiO3.
• To explore the correlation between micro-area catalytic activity and the termination layer of the SrRuO3 films.
• To elucidate the relationship between the electronic structure and the OER activity of these films.

Main Methods:

• Growth of SrRuO3 films on SrTiO3 substrates utilizing a lattice matching strategy.
• High-resolution imaging of local OER performance using scanning electrochemical microscopy (SECM).
• Complementary electrochemical analysis and density functional theory (DFT) calculations.

Main Results:

• SECM successfully imaged the spatially resolved OER activity across the SrRuO3 film surface.
• A clear relationship was established between the micro-area catalytic activity and the specific termination layer of the film.
• DFT calculations and electrochemical data confirmed the correlation between the electronic structure and OER performance.

Conclusions:

• The termination layer of SrRuO3 films significantly influences local OER activity.
• The electronic structure plays a critical role in determining the catalytic performance for OER.
• Combining advanced microscopy with theoretical calculations provides a powerful approach to understand surface-dependent catalysis.