Analysis of the catalytic activity and electrical characteristics of different modified SnO2 layers for gas sensors

In this work, the effects of additives on the catalytic properties and electrical characteristics of SnO2, nanopowders are investigated using methane as target gas. For the purpose of this study, Pd, Pt and Au were introduced in sol-gel tin oxide nanopowders. Additives nominal weight concentration used were 0.2 and 2%. In order to obtain different additive chemical states, SnO2 grain size and related to that, different additive surface concentrations, calcination treatments at temperatures up to 1000 degreesC were carried out after additive introduction. Comparison of the catalytic and electrical results is discussed as a function of the additive concentration and calcination temperature. (C) 2002 Elsevier Science B.V. All rights reserved.