Snapshot Hyperspectral Imaging (SHI) for Revealing Irreversible and Heterogeneous Plasmonic Processes

Abstract

Plasmon-mediated processes provide unique opportunities for selective photocatalysis, photovoltaics, and electrochemistry. Determining the influence of particle heterogeneity is an unsolved problem because often such processes introduce irreversible changes to the nanocatalysts and/or their surroundings. The challenge lies in monitoring heterogeneous nonequilibrium dynamics via the slow, serial methods that are intrinsic to almost all spectral acquisition methods with suitable spatial and/or spectral resolution. Here, we present a new metrology, snapshot hyperspectral imaging (SHI), that facilitates in situ readout of the tube lens image and first-order diffraction image of the dark-field scattering from many individual plasmonic nanoparticles to extract their respective spectra simultaneously. Evanescent wave excitation with a supercontinuum laser enabled signal-to-noise ratios greater than 100 with a time resolution of only 1 ms. Throughput of ∼100 simultaneous spectra was achieved with a highly ordered nanoparticle array, yielding a spectral resolution of 0.21 nm/pixel. Additionally, an alternative dark-field excitation geometry utilized a combination of a supercontinuum laser and a reflecting objective for polarization-controlled SHI. Using a simplified version of SHI, we temporally resolve on the millisecond time scale the heterogeneous kinetics of an electrochemical surface redox reaction for many individual gold nanoparticles simultaneously.

Copper catalysis at operando conditions—bridging the gap between single nanoparticle probing and catalyst-bed-averaging

“…In a typical experiment, changes in the measured spectra, such as the wavelength shift of the scattering peak, are attributed to chemical or structural changes in the individual particles. DFSS traditionally relies on the use of a grating spectrometer to generate wavelength-resolved single particle scattering spectra 35 , 36 , and is therefore limited to measuring a few tens of particles simultaneously 35 (with one exception where almost 100 particles could be measured 37 ). To increase the number of simultaneously measured particles, so-called hyperspectral spectrometers have been developed 35 .…”

Hot Holes Assist Plasmonic Nanoelectrode Dissolution

“…Multiple gold nanorod spectra were measured simultaneously using a snapshot hyperspectral technique recently developed by us (Figure a) . Gold nanorods were excited with a white-light laser (WhiteLase SC480, Fianium) using prism total internal reflection to create an evanescent wave at the indium tin oxide (ITO) working electrode interface.…”

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

“…We believe the highly sensitive EC-DFS technique offers itself a powerful tool for studying the surface chemistry at the atomic level. If this method can be further combined with a wide field imaging technique [29][30][31] , it may allow characterization of the activity and structure of NCs in a high throughput way.…”