Heterogeneous Reactivity of Palladium Nanoparticles Revealed by Wavelength-Resolved Interferometric Scattering

Area of Science:

• Nanotechnology
• Materials Science
• Physical Chemistry

Background:

• Palladium nanoparticles (Pd NPs) are crucial in various applications.
• High-throughput, label-free detection and in situ reaction monitoring of Pd NPs are needed.
• Establishing structure-function relationships requires precise nanoscale characterization.

Purpose of the Study:

• Introduce wavelength-resolved interferometric scattering (iSCAT) for Pd NP studies.
• Enable detection and in situ monitoring of Pd NPs at catalytically relevant sizes.
• Investigate Pd NP transformations and reactivity.

Main Methods:

• Utilized wavelength-resolved interferometric scattering (iSCAT).
• Spectroscopically discriminated structural outliers of Pd octahedra based on scattering resonances and spectral lineshapes.
• Validated structure-spectral relationships using simulations.
• Tracked changes in single Pd nanocubes (<20 nm) under reactive conditions.

Main Results:

• Successfully discriminated structural outliers in ~90 nm Pd octahedra.
• Demonstrated direct detection of single Pd nanocubes with <20 nm edge length.
• Uncovered interparticle heterogeneity and wavelength-dependent photochemistry in Pd NPs.
• Observed Pd nanoparticle transformations in situ.

Conclusions:

• Wavelength-resolved iSCAT is a powerful tool for studying Pd NP transformations in situ.
• The technique provides new insights into Pd reactivity at the nanoscale.
• iSCAT facilitates robust structure-function relationship establishment for Pd NPs.