UV-enhanced ozone gas sensing response of ZnO-SnO2 heterojunctions at room temperature
Résumé
The sensitivity of ZnO-SnO2 heterojunctions to ozone gas was investigated in this work, the two-phase materials of which were prepared via a hydrothermal route, resulting in nanocomposites in which the formation of heterojunctions was confirmed by microscopy analyses. While the sensing effectiveness of these materials is currently verified for application above 150 °C, these temperatures are here drastically reduced to room temperature by considering sensing activity under continuous UV irradiation, even for ozone concentrations as low as 20 ppb. This approach resulted in a fast sensing response, a short recovery time and a good selectivity compared to other gases, demonstrating a great potential of such heterojunctions for applications in environmental monitoring devices.