Improved sensing performance of WO3 nanoparticles decorated with Ag and Pt nanoparticles

Gas sensors built with metal oxide semiconductors have attracted tremendous attention due to the growing demand for the detection of inflammable, explosive and toxic gases. Herein, to improve the sensing response, WO 3 nanoparticles decorated with Ag and Pt bimetals (Ag and Pt/WO 3 NPs) have been developed via combined hydrolysis and hydrothermal strategies. Such sensors prototypes show high response to acetone ( R a / R g = 250 @ 100 × 10 –6 , 140 °C), which is 6.1 fold as high as that of the pristine WO 3 NPs ( R a / R g = 41 @ 100 × 10 –6 , 140 °C). Moreover, the recovery time of Ag and Pt/WO 3 NPs was reduced from 138 to 13 s compared with that of the pristine WO 3 NPs. The improved acetone sensing performance may be attributed to that the chemical and electronic sensitization of Ag and Pt to WO 3 NPs increases adsorbed oxygen species, speeds up the reaction and thus boosts the sensing response. Our strategy that decoration of dual precious metals onto WO 3 NPs improves the acetone sensing performance may be applied to the gas sensors of other sensing materials. Graphic abstract