Ethanol-sensing characteristics of barium stannate prepared by chemical precipitation

Perovskite-type oxide BaSnO3 has been prepared at reduced temperature. The cubic BaSnO3 phase forms at 400 degreesC when a precipitation method is app lied. Thermal analysis indicates that the decomposition temperature of BaSn (OH)(6) is below 600 degreesC. The trace amounts of BaCO3 in the precipitat e are due to the reaction of barium ions with the atmospheric CO2 in a stro ng basic solution. Conductance measurement between 200 and 550 degreesC ind irectly demonstrates the gas-sensing mechanism of BaSnO3 might be a surface -controlled process. The gas-sensing properties of BaSnO3 to ethanol are fi rst reported. The sensor made of the BaSnO3 prepared by a precipitation met hod exhibits low responses to LPG, petrol, H-2 and CO but high response and good selectivity to ethanol. The as-prepared BaSnO3 is a promising ethanol -sensing material. (C) 2000 Elsevier Science B.V. All rights reserved.