Charge storage and release onto Au and Ag nanoparticles in aqueous medium as probed by optical spectroscopy
Date
2014Source Title
Journal of Spectroscopy and Dynamics
Print ISSN
2249-2704
Electronic ISSN
2249-2712
Publisher
Cognizure
Volume
4
Issue
1
Pages
1 - 5
Language
English
Type
ArticleItem Usage Stats
122
views
views
38
downloads
downloads
Abstract
Gold and silver nanoparticles in aqueous solutions can store negative or positive charges when, respectively, NaBH4, KI are
introduced into the same media. The charge storage can be followed by the spectral shifts in the corresponding surface plasmon resonance
(SPR) bands of these nanoparticles. In a similar way, the kinetics of these two processes can be monitored by the same shifts. Accordingly,
we show that although Au nanoparticles exhibit smaller spectral shifts upon both negative and positive charge storage, when compared with
Ag nanoparticles, their kinetics are faster towards reduction (electron storage) and comparable towards oxidation. Hence, if not the spectral
shifts, the kinetics of the electron storage process can be correlated to the larger electron affinity of Au nanoparticles, when compared with
those of Ag. The similarity of the kinetics towards oxidation must also be related to the small difference between the ionization potentials of
Au and Ag nanoparticles.
Keywords
Au and Ag nanoparticlesSpectral shifts
Electron storage and release
Electron affinities
Ionization potentials