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 applied. Thermal analysis indicates that the decomposition temperature of BaSn(OH)(6) is below 600 degreesC. The trace amounts of BaCO3 in the precipitate are due to the reaction of barium ions with the atmospheric CO2 in a strong basic solution. Conductance measurement between 200 and 550 degreesC indirectly demonstrates the gas-sensing mechanism of BaSnO3 might be a surface-controlled process. The gas-sensing properties of BaSnO3 to ethanol are first reported. The sensor made of the BaSnO3 prepared by a precipitation method 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.