SYNTHESIS OF SnO_2 FILMS FOR ROOM-TEMPERATURE CO DETECTION

摘要

An optimized spray pyrolysis technique was used to prepare thin SnO_2 films doped with ultrafine Pt particles for room-temperature CO detection via resistance measurements. This method makes it possible to achieve uniform dispersion of the Pt particles, catalyzing CO oxidation. The effects of deposition temperature (400-560℃) and Pt content (0.1-5 at.) on the sensitivity of the films were examined. Dynamic and quasisteady-state electrical measurements were made in air containing 3 x 10~-2 CO.SnO_2 films diped with 2 at/100 . Pt exhibited a sharp peak of sensitivity at temperatures between 25 and 100℃.Selsetivity of the films was studied by comparing responses to water vapor, 8 x 10~-3 ethanol ,and 0.1 methane.