Adsorption, Chemical Enhancement, and Low-Lying Excited States of p-Methylbenzenethiol on Silver and Gold Nanoparticle Surfaces: A Surface Enhanced Raman Spectroscopy and Density Functional Theory Study

Rui Wang, Xiao-Ru Shen, Meng Zhang, Rajkumar Devasenathipathy, Ran Pang, De-Yin Wu*, Jingdong Zhang, Jens Ulstrup, Zhong-Qun Tian

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Adsorption and chemical enhancement of p-methylbenzenethiol (PMBT) on silver and gold nanoparticle surfaces have been studied using surface enhanced Raman spectroscopy (SERS) and density functional theory (DFT) calculations. In normal Raman spectra, the Raman intensity of the molecule is sensitive to methyl substitution at the para position. DFT calculations for the Raman spectrum of PMBT reproduces well the Raman spectrum in nonpolar solution relative to PMBT in powder. This accords with the order of the PMBT molecules in the solid. The SERS results of PMBT adsorbed on Au and Ag nanoparticles indicate that the Raman intensity in the low-wavenumber region increases with increasing excitation wavelength. The electronic structures of low-lying excited states have been explored for this increase in different PMBT-S-metal cluster complexes. DFT results indicate that low-energy excited states are in fact present and originate from two types of excitations, one localized at the sulfur–silver/gold bonding region and another one from a charge transfer state excited from PMBT to the silver and gold surfaces. Both interfacial excited states contribute significantly to the chemical enhancement mechanism and change relative Raman intensities of adsorbed PMBT. The chemical bonding interaction and the interfacial energy level alignment are therefore important to understand SERS processes of PMBT adsorbed on noble metal surfaces of nanostructures.
Original languageEnglish
JournalThe Journal of Physical Chemistry Part C
Volume123
Issue number37
Pages (from-to)23026-23036
Number of pages11
ISSN1932-7447
DOIs
Publication statusPublished - 2019

Cite this

@article{4d4b1ff65b844f4581318a28cce8e091,
title = "Adsorption, Chemical Enhancement, and Low-Lying Excited States of p-Methylbenzenethiol on Silver and Gold Nanoparticle Surfaces: A Surface Enhanced Raman Spectroscopy and Density Functional Theory Study",
abstract = "Adsorption and chemical enhancement of p-methylbenzenethiol (PMBT) on silver and gold nanoparticle surfaces have been studied using surface enhanced Raman spectroscopy (SERS) and density functional theory (DFT) calculations. In normal Raman spectra, the Raman intensity of the molecule is sensitive to methyl substitution at the para position. DFT calculations for the Raman spectrum of PMBT reproduces well the Raman spectrum in nonpolar solution relative to PMBT in powder. This accords with the order of the PMBT molecules in the solid. The SERS results of PMBT adsorbed on Au and Ag nanoparticles indicate that the Raman intensity in the low-wavenumber region increases with increasing excitation wavelength. The electronic structures of low-lying excited states have been explored for this increase in different PMBT-S-metal cluster complexes. DFT results indicate that low-energy excited states are in fact present and originate from two types of excitations, one localized at the sulfur–silver/gold bonding region and another one from a charge transfer state excited from PMBT to the silver and gold surfaces. Both interfacial excited states contribute significantly to the chemical enhancement mechanism and change relative Raman intensities of adsorbed PMBT. The chemical bonding interaction and the interfacial energy level alignment are therefore important to understand SERS processes of PMBT adsorbed on noble metal surfaces of nanostructures.",
author = "Rui Wang and Xiao-Ru Shen and Meng Zhang and Rajkumar Devasenathipathy and Ran Pang and De-Yin Wu and Jingdong Zhang and Jens Ulstrup and Zhong-Qun Tian",
year = "2019",
doi = "10.1021/acs.jpcc.9b06431",
language = "English",
volume = "123",
pages = "23026--23036",
journal = "The Journal of Physical Chemistry Part C",
issn = "1932-7447",
publisher = "American Chemical Society",
number = "37",

}

Adsorption, Chemical Enhancement, and Low-Lying Excited States of p-Methylbenzenethiol on Silver and Gold Nanoparticle Surfaces: A Surface Enhanced Raman Spectroscopy and Density Functional Theory Study. / Wang, Rui; Shen, Xiao-Ru; Zhang, Meng; Devasenathipathy, Rajkumar; Pang, Ran; Wu, De-Yin; Zhang, Jingdong; Ulstrup, Jens; Tian, Zhong-Qun.

In: The Journal of Physical Chemistry Part C, Vol. 123, No. 37, 2019, p. 23026-23036.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Adsorption, Chemical Enhancement, and Low-Lying Excited States of p-Methylbenzenethiol on Silver and Gold Nanoparticle Surfaces: A Surface Enhanced Raman Spectroscopy and Density Functional Theory Study

AU - Wang, Rui

AU - Shen, Xiao-Ru

AU - Zhang, Meng

AU - Devasenathipathy, Rajkumar

AU - Pang, Ran

AU - Wu, De-Yin

AU - Zhang, Jingdong

AU - Ulstrup, Jens

AU - Tian, Zhong-Qun

PY - 2019

Y1 - 2019

N2 - Adsorption and chemical enhancement of p-methylbenzenethiol (PMBT) on silver and gold nanoparticle surfaces have been studied using surface enhanced Raman spectroscopy (SERS) and density functional theory (DFT) calculations. In normal Raman spectra, the Raman intensity of the molecule is sensitive to methyl substitution at the para position. DFT calculations for the Raman spectrum of PMBT reproduces well the Raman spectrum in nonpolar solution relative to PMBT in powder. This accords with the order of the PMBT molecules in the solid. The SERS results of PMBT adsorbed on Au and Ag nanoparticles indicate that the Raman intensity in the low-wavenumber region increases with increasing excitation wavelength. The electronic structures of low-lying excited states have been explored for this increase in different PMBT-S-metal cluster complexes. DFT results indicate that low-energy excited states are in fact present and originate from two types of excitations, one localized at the sulfur–silver/gold bonding region and another one from a charge transfer state excited from PMBT to the silver and gold surfaces. Both interfacial excited states contribute significantly to the chemical enhancement mechanism and change relative Raman intensities of adsorbed PMBT. The chemical bonding interaction and the interfacial energy level alignment are therefore important to understand SERS processes of PMBT adsorbed on noble metal surfaces of nanostructures.

AB - Adsorption and chemical enhancement of p-methylbenzenethiol (PMBT) on silver and gold nanoparticle surfaces have been studied using surface enhanced Raman spectroscopy (SERS) and density functional theory (DFT) calculations. In normal Raman spectra, the Raman intensity of the molecule is sensitive to methyl substitution at the para position. DFT calculations for the Raman spectrum of PMBT reproduces well the Raman spectrum in nonpolar solution relative to PMBT in powder. This accords with the order of the PMBT molecules in the solid. The SERS results of PMBT adsorbed on Au and Ag nanoparticles indicate that the Raman intensity in the low-wavenumber region increases with increasing excitation wavelength. The electronic structures of low-lying excited states have been explored for this increase in different PMBT-S-metal cluster complexes. DFT results indicate that low-energy excited states are in fact present and originate from two types of excitations, one localized at the sulfur–silver/gold bonding region and another one from a charge transfer state excited from PMBT to the silver and gold surfaces. Both interfacial excited states contribute significantly to the chemical enhancement mechanism and change relative Raman intensities of adsorbed PMBT. The chemical bonding interaction and the interfacial energy level alignment are therefore important to understand SERS processes of PMBT adsorbed on noble metal surfaces of nanostructures.

U2 - 10.1021/acs.jpcc.9b06431

DO - 10.1021/acs.jpcc.9b06431

M3 - Journal article

VL - 123

SP - 23026

EP - 23036

JO - The Journal of Physical Chemistry Part C

JF - The Journal of Physical Chemistry Part C

SN - 1932-7447

IS - 37

ER -