Ag:ZrO2 nanocomposite thin films derived using a novel sol-gel technique

Thin films of an Ag:ZrO2 nanocomposite (NC) have been prepared using a novel sol-gel technique, employing HCl as a sol stabilizer. The technique facilitates the formation of Ag nanoparticles in a matrix of ZrO2 via thermal annealing, at relatively low temperature (300 degrees C). Transmission electron microscopy (TEM) reveals the formation of nearly spherical Ag nanoparticles embedded in ZrO2. When the annealing temperature is raised from 300 to 450 degrees C, growth of the Ag nanoparticles is observed and their average size is found to increase from 20 to 35 nm. An increase in the annealing duration leads to an increase in the density of the Ag nanoparticles, but does not change their average size. X-ray photoelectron spectroscopic study of the films evidences the conversion of silver oxide into metallic Ag at 300 degrees C. UV-Visible spectroscopy of samples annealed at temperatures above 300 degrees C reveals an absorption peak at similar to 507 nm due to surface plasmon resonance (SPR). An increase in the annealing duration from 2 to 14 h results in an enhancement of the intensity of the absorption peak from 15 to 62%. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim