Photoelectrochemical Analysis of Allowed and Forbidden Multipole Plasmon Modes of Polydisperse Ag Nanorods
2012; American Chemical Society; Volume: 117; Issue: 6 Linguagem: Inglês
10.1021/jp300175y
ISSN1932-7455
Autores Tópico(s)Quantum Dots Synthesis And Properties
ResumoResonant wavelengths of multipole (i.e., higher-order) plasmon resonance of polydisperse Ag nanorods (NRs) and their dependence on incident angle are analyzed by a photoelectrochemical means coupled with spectroscopy. It also allows us to observe nanostructures of multipole-resonant Ag NRs. Multiple dip formation in extinction spectra is caused by selective oxidation of multipole-resonant NRs on the basis of multipole plasmon-induced charge separation on a TiO2 substrate. The dip wavelengths are the dipole resonant wavelengths of the NRs that are dipole- or multipole-resonant at the irradiation wavelength. Even order plasmon modes (mode index number m = 2, 4) of the NRs are forbidden at perpendicular incidence (θ = 0°), and in the present system, the third-order plasmon mode (m = 3) is also forbidden at a specific incident angle, θ = 37.5°.
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