Preparation and gas sensitivity of SnO2 nanopowder homogenously doped with Pt nanoparticles

Platinum (Pt)-doped SnO2 nanopowders were prepared by a new doping method which controls the surface charge by controlling the pH. Individual Pt particles were homogenously doped on the surface of the SnO2 nanoparticles at pH 6. Subsequently, a heat treatment was conducted in a hydrogen atmosphere to remove contaminants and to increase the number of oxygen vacancies of the SnO2 nanopowders. To recognize the sensitivity of the powders, Pt-doped SnO2 gas sensors were fabricated using a dispensing technology on a silicon substrate and tested at 400 degrees C in ethanol and formaldehyde gas, and then compared with sensors fabricated with commercial powders. The test results showed that the SnO2 gas sensors homogenously doped with Pt have sufficient sensitivity for detecting reducing gas. (C) 2008 Elsevier B.V. All rights reserved.