SnO2 thin films modified by the SnO2-Au nanocomposites: Response to reducing gases

The influence of the SnO2 surface modification by the SnO2-Au nanocomposites on conductivity response to such reducing gases as CO and H-2 has been analyzed in the present paper. Both initial SnO2 films, subjected for surface modification, and SnO2-Au nanocomposites were deposited by Successive Ionic Layer Deposition (SILD) method. The SnO2-Au nanocomposites with Au/Sn ratio similar to 1 were synthesized using HAuCl4 and SnCl2 precursors. The thickness of the Au-SnO2 nanolayers varied from 0.7-1.0 nm to 10-15 nm. It was established that the increase in the thickness of the SnO2-Au nanocomposite layer formed on the surface of the SnO2 films was accompanied by both the improvement of sensor response and the decrease in response and recovery times. An explanation of the observed effects has been proposed. (C) 2009 Elsevier B.V. All rights reserved.