Evolution of the optical spectra of an Ag/mesoporous SiO2 nanostructure heat-treated in air and H2 atmospheres

Evolution of the various optical spectra of Ag nanoparticles dispersed in mesoporous SiO2 after heating alternately in H2 and air atmospheres has been investigated. It has been observed that, in accordance with alternate heat treatment in H2 and air, surface plasmon resonance (SPR) absorption of the...

Full description

Saved in:
Bibliographic Details
Published in:Nanotechnology 2007-05, Vol.18 (18), p.185710-185710 (5)
Main Authors: Hu, Jinlian, Lee, Woong, Cai, Weiping, Tong, Liuniu, Zeng, Haibo
Format: Article
Language:English
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Evolution of the various optical spectra of Ag nanoparticles dispersed in mesoporous SiO2 after heating alternately in H2 and air atmospheres has been investigated. It has been observed that, in accordance with alternate heat treatment in H2 and air, surface plasmon resonance (SPR) absorption of the Ag/mesoporous SiO2 nanostructure alternately appeared and disappeared and its Raman scattering spectra reversibly increased and decreased. In contrast, its photoluminescence (PL) spectra alternately disappeared and appeared, whereas the infrared (IR) spectra did not change. Such novel optical sensitivities of silver nanoparticles are discussed on the basis of the changes in chemical states of silver induced by the interaction of silver nanoparticles with the atmospheres and the hosting medium. It is suggested that the chemical state of silver in mesoporous SiO2 changes reversibly between Ag and the Ag+ ion by the redox process.
ISSN:0957-4484
1361-6528
DOI:10.1088/0957-4484/18/18/185710