Application of Au/TiO2–WO3 material in visible light photoreductive ozone sensors

Abstract Various ratios of TiO 2 –WO 3 and Au/TiO 2 –WO 3 composites were prepared as ozone-sensing materials. These materials were characterized by temperature-programmed reduction, UV–visible reflective spectra, transmission electron microscopy, and X-ray diffraction. A 460-nm blue LED light source was used for the detection of gaseous ozone, and the sensing properties of various ratios of TiO 2 –WO 3 were measured. Among the various weight ratios of TiO 2 –WO 3 , the sensor response of the TiO 2 –WO 3 (3:1) was the highest obtained response (23.8) to 2.5 ppm ozone. By adding 0.1 wt.% Au to the TiO 2 –WO 3 (3:1), the sensor response was improved to 64.0. The ozone-sensing properties are attributed to the mechanism of adsorption, photoreduction, desorption, and the surface reaction processes of ozone.