Observing atomic layer electrodeposition on single nanocrystals surface by dark field spectroscopy.

Area of Science:

• Nanomaterials Science
• Surface Chemistry
• Electrochemistry

Background:

• Underpotential deposition (UPD) is crucial for tailoring catalytic surface electronic structures at the atomic level.
• Precisely controlling and probing UPD on nanoparticle surfaces remains a significant challenge.
• Atomic-level control is essential for engineering highly active electrocatalysts.

Purpose of the Study:

• To develop a method for in situ observation of silver underpotential deposition on gold nanocrystals.
• To enable precise control and probing of sub-monolayer to monolayer atomic deposition on nanoparticles.
• To understand the UPD process on nanocrystals for novel nanomaterial creation.

Main Methods:

• Designed a highly sensitive electrochemical dark field scattering setup for in situ observation.
• Observed silver electrodeposited on gold nanocrystals from sub-monolayer to one monolayer.
• Reconstructed optical "cyclic voltammograms" from spectral variations of single nanocrystals.

Main Results:

• Successfully observed and analyzed silver underpotential deposition on gold nanocrystals in situ.
• Demonstrated the capability to track atomic layer deposition from sub-monolayer to monolayer coverage.
• Provided a unique method to understand UPD processes at the single nanocrystal level.

Conclusions:

• The developed technique allows unprecedented insight into underpotential deposition on nanocrystal surfaces.
• This method is essential for the rational design and synthesis of advanced nanomaterials for catalysis.
• Enables precise engineering of catalytic surfaces at the atomic level for enhanced electrocatalytic activity.