Core-shell Au-Ag nanoparticles in dielectric nanocomposites with plasmon-enhanced fluorescence: A new paradigm in antimony glasses

Abstract

The nano era demands the synthesis of new nanostructured materials, if possible by simplified techniques, with remarkable properties and versatile applications. Here, we demonstrate a new single-step reproducible melt-quench methodology to fabricate core-shell bimetallic (Au 0 Ag 0 ) nanoparticles (28 89 nm) embedded glasses (dielectrics) by the use of a new reducing glass matrix, K 2 O B 2 O 3 Sb 2 O 3 (KBS) without applying any external reducing agent or multiple processing steps. The surface plasmon resonance (SPR) band of these nanocomposites embedded in KBS glass is tunable in the range 554-681 nm. More remarkably, taking advantage of the selective reduction capability of Sb 2 O 3 , this single-step methodology is used to fabricate inter-metallic: rare-earth ions co-embedded (Au Ag:Sm 3+ ) dielectric (glass)-based-dnanocomposites and study the effect of enhanced local fi eld on the red upconversion fl uorescence of Sm 3+ ions at 636 nm. The enhancement is found to be about 2 folds. This single-step in-situ selective reduction approach can be used to fabricate a variety of hybrid-nanocomposite devices for laser based applications (see supplementary information).

Nanocrystalline intermetallics and alloys

“…However, design of facile and general strategies for the synthesis of other intermetallics and alloys with high surface areas still remains a great challenge. Undoubtedly, the emergence and development of nanoscience and nanotechnology offer new opportunities in this area [14][15][16][17][18].…”

“…However, design of facile and general strategies for the synthesis of other intermetallics and alloys with high surface areas still remains a great challenge. Undoubtedly, the emergence and development of nanoscience and nanotechnology offer new opportunities in this area [14][15][16][17][18].Recently, we developed a general strategy for the synthesis of various nanocrystals, whereby noble metal ions can be reduced to monodisperse noble metal nanocrystals by a mixture of ethanol and linoleic acid [19]. However, attempts to synthesize intermetallics and alloys of noble and non-noble metals (e.g., FePt, NiPt, and CoPd) with this strategy were unsuccessful, mainly due to the low reducing power of ethanol and linoleic acid.…”

Nonstoichiometric Polyelectrolyte Complexes: Smart Nanoreactors for Alloy and Multimetallic Catalyst

“…To understand the dynamics of the formation of alloy NPs, UV-Vis spectra were recorded for a solution with equal concentration but varying molar ratio of both metal precursors. It is reported that in case of alloy NPs, plasmon band shifts toward another one (either blue or red) if the molar ratio of one increase by keeping constant of another precursors [10]. The mono-metallic PEC-AuNPs showed characteristic peak at 523 nm (Fig.…”

“…HRTEM analysis (inset of Fig. 2e) shows clear lattice fringes of the NPs with an interplanar distance with lattice fringes 0.24 nm corresponding to (111) plane, which indicates that the PECs supported NPs are well crystalline [10]. To understand the dynamics of the formation of alloy NPs, UV-Vis spectra were recorded for a solution with equal concentration but varying molar ratio of both metal precursors.…”

Microwave-assisted biosynthesis of gold–silver alloy nanoparticles and determination of their Au/Ag ratio by atomic absorption spectroscopy

“…Metal alloy nanoparticles (NPs) such as Au-Ag alloy NPs have received considerable attention in recent years because of their unique properties and potential applications in catalysis, photonics, optoelectronics, biological tagging and pharmaceutical applications [1][2][3]. The performance of Au-Ag alloy NPs depends critically on their size, shape and composition [4].…”