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, WO₃ nanoparticles decorated with Ag and Pt bimetals (Ag and Pt/WO₃ 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 WO₃ NPs (R_a/R_g = 41 @ 100 × 10^–6, 140 °C). Moreover, the recovery time of Ag and Pt/WO₃ NPs was reduced from 138 to 13 s compared with that of the pristine WO₃ NPs. The improved acetone sensing performance may be attributed to that the chemical and electronic sensitization of Ag and Pt to WO₃ NPs increases adsorbed oxygen species, speeds up the reaction and thus boosts the sensing response. Our strategy that decoration of dual precious metals onto WO₃ NPs improves the acetone sensing performance may be applied to the gas sensors of other sensing materials.