One-step hydrothermal synthesis of uniform Ag-doped SnO2 nanoparticles for highly sensitive ethanol sensing

Noble metal doping is considered to be an efficient way to promote the gas sensing performances of metal oxide semiconductor nanomaterials . In this study, uniform silver (Ag)-doped tin dioxide (SnO 2 ) nanoparticles were successfully synthesized through a facile one-step hydrothermal route. The diameter of Ag/SnO 2 nanoparticles is less than 10 nm. Compared with pure SnO 2 -based sensor, the Ag/SnO 2 -based sensors are found to effectively improve their sensitivity and selectivity to ethanol. In particular, the 6% Ag/SnO 2 -based sensor displays a high response (Ra/Rg = 135) to 50 ppm ethanol at 180 °C. The enhancement of ethanol sensing properties of the 6% Ag/SnO 2 sample due to the small size of SnO 2 and catalytic sensitization effect of Ag, as well as the Schottky barrier forms between SnO 2 and Ag. These results suggest that the Ag-doped SnO 2 nanoparticles acting as a promising functional composite material have potential application for ethanol sensors.