Chemical interface damping in single gold nanorods coated with silver via hot electron‐mediated photoreduction

Abstract

Herein, we investigated the photoreduction of silver (Ag) ions on gold nanorods coated with mesoporous silica shell (AuNRs@mSiO2) induced by hot electrons generated in Au via localized surface plasmon resonance (LSPR) excitation. In addition, we investigated chemical interface damping (CID) using pyridine as the adsorbate in single Ag‐coated AuNRs@mSiO2. The Ag deposition caused a blue shift and linewidth broadening of the LSPR peak of the AuNRs@mSiO2. The subsequent chemisorption of pyridine on Ag‐coated AuNRs@mSiO2 resulted in a red shift and additional LSPR linewidth broadening. Finally, we demonstrated real‐time time‐dependent changes in LSPR peak wavelength and linewidth during the sequential processes of hot electron‐mediated Ag deposition and pyridine adsorption on a single AuNR@mSiO2 in a flow cell. Therefore, we provided a deep understanding of hot electron‐triggered Ag coating and CID induced by pyridine adsorption in single AuNRs@mSiO2 coated with Ag.

Tuning of chemical interface damping in single gold nanorods through pH-dependent host–guest interactions using cucurbit[6]uril

“…3–5 Recently proposed, CID involves the direct transfer of hot electrons induced through plasmons on the metal surface to the empty orbitals (lowest unoccupied molecular orbital, LUMO) of adsorbate molecules. 6–14 Among various AuNPs, anisotropic gold nanorods (AuNRs) are mainly used in studying CID owing to their unique optical properties stemming from localized surface plasmon resonance (LSPR), offering tunable plasmon wavelengths based on adjustable morphology. 13–15 CID in AuNRs primarily results from strong covalent bonds between AuNR and sulfur or nitrogen atoms.…”