Au-loaded mesoporous WO3: Preparation and n-butanol sensing performances

Abstract

Au-loaded mesoporous WO3 was synthesized by nanocasting method. Mesoporous structure provided a large specific surface area, and the noble metal (Au) improved the catalytic efficiency. The above two characteristics played crucial roles in enhancing the performance of the gas sensors. The as-synthesized materials were deduced by X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The obtained materials showed ordered mesoporous structure with excellent crystallinity and the pore size was about 10.8nm which matched with Barrett-Joyner-Halenda analysis. Static test system was employed to measure volatile organic compounds (VOCs) (such as methanol, ethanol, isopropanol and n-butanol) sensing properties for the sensors using mesoporous WO3 and different weight ratios of Au-loaded (0.2%, 0.5% and 1.0%) mesoporous WO3. The sensors loaded with Au exhibited much higher sensitivity and selectivity to n-butanol in this work. Furthermore, Au-loaded materials showed lower operating temperature.