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Structural Change of a Single Ag Nanoparticle Observed by Dark‐field Microspectroscopy
Author(s) -
Pang Jie,
Liu HaiLing,
Li Jian,
Zhai TingTing,
Wang Kang,
Xia XingHua
Publication year - 2018
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201701148
Subject(s) - silver nanoparticle , dark field microscopy , nanoparticle , materials science , nanosensor , surface plasmon resonance , indium tin oxide , nanotechnology , silver oxide , chemical engineering , analytical chemistry (journal) , chemistry , microscopy , optics , layer (electronics) , physics , engineering , chromatography
Silver nanoparticles (AgNPs) have been widely used as photocatalysts and nanosensors. Observation of the spectroscopy of a single AgNP greatly helps us understand the catalytic characteristics and morphology change of the AgNP during reactions. In the present study, AgNPs physically adsorbed on indium tin oxide (ITO) conductive glass were electrochemically reduced and oxidized, and the plasmonic resonance Rayleigh scattering (PRRS) spectrum of an individual AgNP was observed under a dark‐field microscopy (DFM) equipped with a spectrometer. The electrochemical oxidization of the AgNP under constant potential caused a redshift of the PRRS peak for 30±5 nm. However, electrochemical reduction of the AgNP could not make the PRRS peak completely shift back to the initial position. In situ AFM and SEM characterization confirmed that very small Ag fragments (<10 nm) formed around the AgNP core during electrochemical oxidization. Results showed that dark‐field microspectroscopy could be used as a sensitive tool for estimating the morphology/structural changes of nanoparticles that can hardly be observed through the cyclic voltammograms of multiple AgNPs.