The Sb2O3 redox route to obtain copper nanoparticles in glasses with plasmonic properties†
Abstract
A new route for the production of oxide glasses containing copper nanoparticles was explored. The antimony(III) oxide redox route allowed the use of the reducing properties of α-Sb2O3 during melting to decrease the oxidation number of copper ions in the glassy matrix. Such glasses have different CuII/CuI ratios in their composition, as well as different metallic copper nanoparticles with different size distributions depending on Sb2O3 content. The electronic spectrum of 0.3NaPO3–0.6Sb2O3–0.1CuO glass showed a band at 585 nm assigned to the localized surface plasmon resonance transition from copper nanoparticles, which is a very important property for surface-enhanced spectroscopies. Raman spectroscopy studies of these glasses showed that the short range structure around Sb atoms is closely related to the high temperature β-Sb2O3 phase. Upon heating, α-Sb2O3 → α-Sb2O4 → β-Sb2O4 → β-Sb2O3 phase transitions occurred with increasing temperatures. The short range structures of the glass-forming liquid and the resulting glass were shown to be related to the most stable phase at the melting temperature. Surface enhanced fluorescence spectra from ErIII ions, induced by the presence of copper nanoparticles, could be observed in doped glasses.