Enhanced Zn/ZnO Heterointerfaces via Pulsed-Potential Electrochemical Reconstruction for Highly Selective CO₂...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical carbon dioxide reduction reaction (CO2RR) requires efficient, low-cost cathodes.
• Single-phase metals face scaling limitations in CO2RR.
• Developing novel heterointerfaces is crucial for enhancing CO2RR performance.

Purpose of the Study:

• To engineer advanced Zn/ZnO heterointerfaces for improved CO2RR.
• To investigate the effect of pulsed-potential reconstruction on catalyst performance.
• To provide a scalable method for CO2-to-CO conversion.

Main Methods:

• Utilized pulsed-potential square wave voltammetry (SWV) to reconstruct ZnO nanoparticles.
• Analyzed catalyst structure and composition using TEM/FFT and XPS.
• Evaluated electrocatalytic performance in an H-cell setup.

Main Results:

• SWV successfully generated discrete metallic Zn nanoislands on ZnO surfaces, forming abundant Zn/ZnO heterointerfaces.
• The SWV-ZnO catalyst exhibited a balanced Zn(0)/Zn(II) ratio and stabilized the *COOH intermediate.
• Achieved a peak CO Faradaic efficiency of 90% and a partial current density of 5.3 mA/cm2 at -1.05 V vs RHE.
• Outperformed pristine zinc nanoparticles and potentiostatic reconstruction methods.

Conclusions:

• Pulsed-potential electrochemical reconstruction is a rapid and scalable route to engineer effective heterointerfaces.
• The SWV-ZnO catalyst demonstrates significant potential for sustainable CO2-to-CO conversion.
• This approach offers a practical blueprint for advancing CO2RR technologies.