Enhanced Room Temperature Oxygen Sensing Properties of LaOCI-SnO2 Hollow Spheres by UV Light Illumination

In this paper, a facile and elegant Green Chemistry method for the synthesis of SnO2 based hollow spheres has been investigated. The influences of doping, crystallite morphology, and operating condition on the O-2 sensing performances of SnO2 based hollow-sphere sensors were comprehensively studied. It was indicated that, compared with undoped SnO2, 10 at. % LaOCl-doped SnO2 possessed better O-2 sensing characteristics owing to an increase of specific surface area and oxygen vacancy defect caused by LaOCl dopant. More importantly, it was found that O-2 sensing properties of the 10 at. % LaOCl SnO2 sensor were significantly improved by ultraviolet light illumination, which was suited for room-temperatureO(2) sensing applications. Besides, this sensor also had a better selectivity to O-2 with respect to H-2, CH4, NH3, and CO2. The remarkable increase of O-2 sensing properties by UV light radiation can be explained in two ways. On one hand, UV light illumination promotes the generation of electron hole pairs and oxygen adsorption, giving rise to high O-2 response. On the other hand, UV light activates desorption of oxygen adsorbates when exposed to pure N-2, contributing to rapid response/recovery speed. The results demonstrate a promising approach for room temperature O-2 detection.