Optical Properties and XPS-Characterization of Ag/Au Bimetallic Nanoparticles in Porous Sol-Gel Silica Films

• Main Authors: Eremenko, A.M., Smirnova, N.P., Yashan, H.R., Ozkaraoglu, E., Ertas, G., Suzer, S.
• Format: Article
• Language: English
• Published: Інститут хімії поверхні ім. О.О. Чуйка НАН України 2010
• Series: Хімія, фізика та технологія поверхні
• Online Access: http://dspace.nbuv.gov.ua/handle/123456789/28961

Ag/Au bimetallic nanoparticles (BMNP) in porous sol-gel silica films on glass substrates were obtained via hydrolysis of tetraethylorthosilicate (TEOS) in presence of template agent Pluronic P123 and definite amounts of AgNO3 and HAuCl4 by dip-coating procedure followed by a UV-irradiation and thermal treatment. UV-vis spectroscopy was employed to follow the changes in the position and intensity of the surface plasmon resonance band of the resulting BMNP, SEM was employed for morphology investigation. X-ray photoelectron spectroscopy (XPS) was used to determine the chemical states of Au and Ag as well as the surface composition of the resultant films. By utilizing the charging characteristics of the films prepared on a silicon wafer, via application of an external voltage bias, it was found that the Au and Ag nanoparticles are retained within the silica matrix and demonstrate similar charging behavior. Depending on the coating sequences of glass substrates by the silica sol precursors (Au/SiO2 or Ag/SiO2), resultant BMNP within silica film have alloy (Au/SiO2-Ag/SiO2) or core-shell (Ag/SiO2-Au/SiO2) structure.