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°C when a precipitation method is applied. Thermal analysis indicates that the decomposition temperature of BaSn(OH)6 is below 600°C. 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°C 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, H2 and CO but high response and good selectivity to ethanol. The as-prepared BaSnO3 is a promising ethanol-sensing material.