Mapping Surface and Subsurface Atomic Structures of Au@Pd Core-Shell Nanoparticles in Three Dimensions

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• 3D atomic structures of nanomaterials are vital for structure-functionality correlations.
• Resolving these structures at high resolution is challenging due to imaging limitations.

Purpose of the Study:

• To determine the 3D atomic surface and subsurface structures of Au@Pd core-shell nanoparticles.
• To correlate these structures with electronic and surface chemical properties.

Main Methods:

• Atomic-resolution electron tomography (AET) was employed to image nanoparticle structures.
• Spectroscopic and electrochemical measurements were used to analyze properties.

Main Results:

• Intermixing of gold (Au) and palladium (Pd) significantly influences surface and subsurface structures.
• A negative correlation was found between intermixing, bond disorder, and tensile strain.
• Varying surface structures correlate with altered electronic and chemical properties at different Au/Pd ratios.

Conclusions:

• This work elucidates complex surface/subsurface structures in realistic nanomaterials.
• It enhances understanding of single-atom level structure-functionality relationships in nanostructures.