Mesoporous WO₃ modified by Au nanoparticles for enhanced trimethylamine gas sensing properties

Abstract

In this paper, KIT-6 is used as a template to prepare ordered mesoporous materials WO₃ and Au-loaded WO₃ (Au-WO₃). The pristine WO₃ sensor and the Au-WO₃ sensor are fabricated for the detection of 19 important gases, such as trimethylamine, formaldehyde and CS₂. The results show that the Au-WO₃ sensor has better selectivity and higher response to TMA. At a working temperature of 268 °C, the response (R_a/R_g) of the Au-WO₃ sensor to 100 ppm of TMA is 41.56 and the response time is 1 s. In addition, the sensor has excellent response/recovery capabilities and stability. These high sensing performances are mainly attributed to the electronic and chemical sensitization of the noble metal Au and the presence of a high specific surface area supported by the mesoporous structure. Therefore, Au-doped mesoporous WO₃ should be a promising material for a high performance TMA gas sensor.