Au/SiO2 nanoparticles in TiO2:Sm3+ films for improved fluorescence sensing of oxygen. Issue 45 (15th November 2017)

• Record Type: Journal Article
• Authors: Dolgov, Leonid; Eltermann, Marko; Lange, Sven; Kiisk, Valter; Zhou, Lei; Shi, Jianxin; Wu, Mingmei; Jaaniso, Raivo
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 45(2017)
• Page Start: 11958
• Page End: 11964
• Publication Date: 2017-11-15
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7tc03704j
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Increase–decrease in oxygen gas concentration results in increase–decrease in fluorescence of TiO2 :Sm 3+ films; this effect is especially pronounced around the Au/SiO2 nanoparticles with which the samples are decorated. Abstract : A strong increase in Sm 3+ fluorescence intensity caused by oxygen gas is revealed for TiO2 :Sm 3+ films decorated with Au/SiO2 nanoparticles in spite of the general view of oxygen as a quenching agent. Microluminescence studies revealed that emission from Sm 3+ ions excited by UV light is concentrated around Au/SiO2 nanoparticles, which implies its sensitization by gold. Periodic changes in the oxygen concentration in the O2 :N2 gaseous mixture led to respective modulation of the intensity of Sm 3+ fluorescence. The changes in fluorescence intensity were up to 10 times more pronounced for the samples decorated with Au/SiO2 nanoparticles in comparison with virgin TiO2 :Sm 3+ films. It is suggested that Sm 3+ fluorescence is sensitized by energy transfer from gold clusters presented on the surface of the Au/SiO2 nanoparticles. The oxygen-sensing effect is explained by the model in which oxygen changes the state of energy accepting defects in the TiO2 lattice and in such a way prevents their participation in quenching of Sm 3+ fluorescence.