Gas sensing properties of In2O3 and Au-doped In2O3 films for detecting carbon monoxide in air

Catalytic and sensing properties of several metal oxides in the reaction of CO oxidation and in the sensor detection of CO in air have been studied and compared to each other. Indium. oxide has been found to be, the most sensitive and possessing a relatively low catalytic activity in the oxidation of CO. Possible reasons for the high activity of the indium. oxide sensor matrix are discussed. The promoting effect of An and Pd doping of In2O3 in the detection of CO in air has been studied, and a mechanism explaining the enhanced sensor response of Au-doped In2O3 has been proposed. A change in humidity has no significant effect on the sensor response of Au-doped In2O3 in the detection of CO in air.