Room temperature UV-Vis activated NO2 gas sensor-based Mg-doped zinc oxide nanopowders

Mg-doped ZnO (MZO) nanopowders were synthesized by sol-gel process. These samples are then characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence (PL) analyses. Resistive sensors based on Mg-doped ZnO thick layers deposited on alumina substrates equipped with platinum interdigitated electrodes were fabricated and used as UV-Vis light activated NO2 sensors. The dark and illumination conditions are both utilized to perform NO2 gas sensing tests by exposing the sensors to UV-Vis radiation (lambda = 400 nm). Under irradiation condition, NO2 detection with Mg-doped ZnO sensor could be successfully performed even to room temperature (30 degrees C). Furthermore, photoactivation also promoted NO2 sensitivity and shortened the signal recovery of Mg-doped ZnO sensors compared to undoped one. Results demonstrated that Mg-doped ZnO might be promising sensing materials for the detection of NO2 under UV-Vis illumination.