In this paper, to improve the sensing performances, the layers of SnO2/WO3 complex nanoparticles, instead of pure SnO2 or WO3, were applied for sensing nitrogen oxide (NO) gas. In general, the SnO2 and WO3 nanoparticles provide a large sensing area and, respectively, possess well sensing capability for NO and NO2 gases. Because NO gas is prone to be transformed into NO2 gas in the environment, the gas sensors with SnO2:WO3 (1:0.25) complex nanoparticle sensing layer exhibited better NO sensing response compared with the gas sensors with pure SnO2 nanoparticle sensing layer. Furthermore, by performing an annealing process at 500 °C and then depositing a gold (Au) catalytic metal layer on the annealed SnO2/WO3 complex nanoparticles, the resulting NO gas sensors exhibited the sensing response of 10.61 under the NO gas concentration of 1 ppm. Moreover, the lowest detection limit of the NO gas sensors with Au covered SnO2:WO3 (1:0.25) complex nanoparticle sensing layer was also extended from 200 to 150 ppb compared with the ones without Au catalytic metal.
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering