TY - JOUR
T1 - Characterization of citrates on gold and silver nanoparticles
AU - Wulandari, Priastuti
AU - Nagahiro, Takeshi
AU - Fukada, Nobuko
AU - Kimura, Yasuo
AU - Niwano, Michio
AU - Tamada, Kaoru
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grant Number 26246005 .
Publisher Copyright:
© 2014 Elsevier Inc.
PY - 2015/1/5
Y1 - 2015/1/5
N2 - In this paper, we report different coordinations of citrates on gold (AuNP) and silver (AgNP) nanoparticles, as determined using Fourier transform infrared spectroscopy (FTIR) and molecular orbital (MO) calculations. AuNPs and AgNPs are found to have completely different interactions with the carboxylate anchoring groups, as indicated by their unique asymmetric stretching vibrations in the FTIR spectra. The νas (COO-) of citrate exhibits a high-frequency shift resulting from the formation of a unidentate coordination on AuNPs, whereas this vibration exhibits a low-frequency shift as a result of ionic bond formation on AgNPs, as predicted from the MO calculations of the corresponding metal complex salts. The enhancement in the IR signals when their vibration direction was perpendicular to the nanoparticle surface revealed the influence of localized surface plasmons excited on the metal nanoparticles.
AB - In this paper, we report different coordinations of citrates on gold (AuNP) and silver (AgNP) nanoparticles, as determined using Fourier transform infrared spectroscopy (FTIR) and molecular orbital (MO) calculations. AuNPs and AgNPs are found to have completely different interactions with the carboxylate anchoring groups, as indicated by their unique asymmetric stretching vibrations in the FTIR spectra. The νas (COO-) of citrate exhibits a high-frequency shift resulting from the formation of a unidentate coordination on AuNPs, whereas this vibration exhibits a low-frequency shift as a result of ionic bond formation on AgNPs, as predicted from the MO calculations of the corresponding metal complex salts. The enhancement in the IR signals when their vibration direction was perpendicular to the nanoparticle surface revealed the influence of localized surface plasmons excited on the metal nanoparticles.
KW - Carboxylate
KW - Infrared spectroscopy
KW - Metal nanoparticles
KW - Vibration of adsorbed molecules
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U2 - 10.1016/j.jcis.2014.09.078
DO - 10.1016/j.jcis.2014.09.078
M3 - Article
AN - SCOPUS:84908583837
VL - 438
SP - 244
EP - 248
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
SN - 0021-9797
ER -