Strain-Modulated Tuning of Rashba Signature and Catalytic Activity on Oxynitride Surface: Facet Matters.

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• Strontium tantalum oxynitride (SrTaO2N) is a rare semiconducting perovskite.
• It exhibits excellent aqueous stability and a narrow band gap.
• These properties make it a promising catalyst for the hydrogen evolution reaction (HER).

Purpose of the Study:

• To investigate the mechanistic insights of electrochemical HER on SrTaO2N surfaces.
• To understand the role of electronic structure and strain on catalytic activity.
• To explore strain-induced effects on surface charge and catalytic performance.

Main Methods:

• First-principles density functional theory (DFT) calculations.
• Analysis of hydrogen adsorption free energy (ΔGH) on low-indexed surfaces (001 and 110).
• Examination of electronic structure and elemental contributions to band edges.

Main Results:

• Computed ΔGH values indicate favorable catalytic activity for HER on the studied facets.
• Electronic structure analysis identified elemental contributions to valence and conduction band edges.
• Biaxial strain was found to enhance the selectivity of SrTaO2N for hydrogen evolution.

Conclusions:

• SrTaO2N demonstrates significant potential as an electrocatalyst for HER.
• DFT calculations provide valuable mechanistic understanding of HER on its surfaces.
• Strain engineering offers a viable strategy to optimize the catalytic performance of SrTaO2N.