XPS and thermal studies of silver doped SiO2 matrices for plasmonic applications

Silver nanocrystals doped SiO2 matrices were synthesized through sol-gel route using acid catalyst. The prepared silica matrices with different concentrations of silver were annealed at different temperatures and characterized using, XRD, FTIR, Absorption spectroscopy, XPS, thermogravimetric and differential thermal analysis. The XRD data confirm the amorphous nature of silica and crystalline nature of silver nanocrystals. Using the Fourier-transform infrared red spectrum the formation of silica glass was confirmed. The characteristic Surface Plasmon Resonance of silver nanoparticles obtained around 400 nm from the absorption spectrum. The observed blue shift and skewness in SPR with increasing silver concentrations were studied. The 3d doublet state of silver at a binding energy of 368.4 eV with the splitting of 6 eV obtained in XPS confirm the state Ag-0 along with the presence of a minor quantity of silver (II) oxide. The thermal stability and nature were analyzed using TGA-DTG and DTA and showed good thermal stability from 400 degrees C to higher temperatures. (C) 2019 Elsevier Ltd. All rights reserved.