Synthesis and spectroscopic characterization of Ag-Cu alloy nanoparticles prepared in various ratios

Ag-Cu alloy nanoparticles of various compositions were synthesized by the polyol process and characterized by UV-Visible, fluorescence and XRD techniques. The particle size calculated by Debye Scherrer's equation was found to decrease from 28 to 18 nm with the increase in mole fraction of Cu in Ag-Cu alloy nanoparticles due to crystal lattice contraction. The appearance of the spectral peaks of alloy nanoparticles between the peaks of pure Ag and Cu revealed the formation of alloy nanoparticles. The optical properties were found to vary with composition and the Ag-Cu alloy of 1:1 composition showed a maximum value of extinction coefficient. The results of fluorescence spectroscopy revealed Cu as a quencher. Physical parameters, such as the total number of atoms in alloy nanoparticle, number of binding sites, binding constant and free energy of binding were calculated from fluorescence data. (C) 2012 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.