Thermally activated platinum as VOC sensing material for work function type gas sensors

Heating up Pt films or Pt dispersions supported on a metal oxide to a few hundred degree Celsius in ambient air for some minutes causes the formation of reactive species on the surface that are supposedly derivates of adsorbed oxygen. When the specimen is subsequently cooled down to room temperature, these species are still active for several days. They cause a gas response at room temperature to a large variety of hydrocarbons, as measured by change in work function. The interaction of volatile organic compounds (VOCs) and the activity duration heavily depend on the composition of the materials. The results provide the basis for room temperature gas detection with intermittent activation at elevated temperatures. (C) 2009 Elsevier B.V. All rights reserved.