Evolution from the plasmon to exciton state in ligand-protected atomically precise gold nanoparticles

Authors

Meng Zhou, Carnegie Mellon University
Chenjie Zeng, Carnegie Mellon University
Yuxiang Chen, Carnegie Mellon University
Shuo Zhao, Carnegie Mellon University
Matthew Y. Sfeir, CUNY Graduate CenterFollow
Manzhou Zhu, Anhui University
Rongchao Jin, Carnegie Mellon University

Document Type

Article

Publication Date

10-24-2016

Abstract

The evolution from the metallic (or plasmonic) to molecular state in metal nanoparticles constitutes a central question in nanoscience research because of its importance in revealing the origin of metallic bonding and offering fundamental insights into the birth of surface plasmon resonance. Previous research has not been able to probe the transition due to the unavailability of atomically precise nanoparticles in the 1-3 nm size regime. Herein, we investigate the transition by performing ultrafast spectroscopic studies on atomically precise thiolate-protected Au₂₅, Au₃₈, Au₁₄₄, Au₃₃₃, Au_∼520 and Au_∼940 nanoparticles. Our results clearly map out three distinct states: metallic (size larger than Au₃₃₃, that is, larger than 2.3 nm), transition regime (between Au₃₃₃ and Au₁₄₄, that is, 2.3-1.7 nm) and non-metallic or excitonic state (smaller than Au₁₄₄, that is, smaller than 1.7 nm). The transition also impacts the catalytic properties as demonstrated in both carbon monoxide oxidation and electrocatalytic oxidation of alcohol.

Comments

This article was originally published in Nature Communications, available at https://doi.org/10.1038/ncomms13240

This work is distributed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).