Photon stimulated ozone sensor based on indium oxide nanoparticles II: Ozone monitoring in humidity and water environments

In our previous work (part I), a compact energy-saving photostimulated ozone sensor has been demonstrated, which can monitor a wide concentration range of ozone in synthesized air. However, for practical purposes such as environmental ozone detection in air or the monitoring of ozone concentration for water treatment applications, the interference of water vapor/humidity must be considered, because it has a large influence on the sensor performance. In the present work, the photostimulated ozone sensor has been used to detect ozone in a high-humidity gas environment. Sensor signals were found to be reproducible. By sealing the sensor chamber with a porous hydrophobic membrane, which prevented the passage of liquid water, submerged measurements were carried out. A mechanism of the influence of humidity on the photostimulated sensor has been proposed based on electrical measurements.