Enhanced Room Temperature Oxygen Sensing Properties of LaOCl–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 O₂ 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 O₂ sensing characteristics owing to an increase of specific surface area and oxygen vacancy defect caused by LaOCl dopant. More importantly, it was found that O₂ sensing properties of the 10 at. % LaOCl–SnO₂ sensor were significantly improved by ultraviolet light illumination, which was suited for room-temperature O₂ sensing applications. Besides, this sensor also had a better selectivity to O₂ with respect to H₂, CH₄, NH₃, and CO₂. The remarkable increase of O₂ 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 O₂ response. On the other hand, UV light activates desorption of oxygen adsorbates when exposed to pure N₂, contributing to rapid response/recovery speed. The results demonstrate a promising approach for room-temperature O₂ detection