One-Step Preparation and Fluorescence Enhancement Effect in SiO2/Eu2+ Doped with Ag Nanowires

Eu2+ single-doped SiO2 (SiO2/Eu2+) and Eu2+, Ag nanowires co-doped SiO2 (SiO2/Eu2+-Ag) luminescent nanomaterials were prepared by an efficient one-step sol-gel method. Their microstructure and optical properties were characterized, and the fluorescence enhancement of Eu2+ by Ag nanowires was investigated. The experimental results indicate that the average diameter of Ag nanowires doped is 12.5 nm, and the length-diameter ratio is 30. The Ag nanowires cannot only enhance the light absorption of SiO2/Eu2+ in the range of 230-350 nm, but also reduce the fluorescence lifetime of Eu2+. More importantly, the emission intensity is enhanced after doping Ag nanowires, and the red shift phenomenon of the emission spectrum is observed, red shift occurs between 10 and 56 nm. The highest fluorescence intensity is accessed under the Ag doping concentration of 0.10 %. Additionally, the emission of SiO2/Eu2+ with 0.10 % of Ag doping at 456 nm is 16 times stronger than that of pure SiO2/Eu2+. The present results indicate that the fluorescence enhancement is attributed to the local field enhancement and the increased radiative decay rates induced by Ag nanowires