Enhanced Room Temperature Oxygen Sensing Properties of LaOCl-SnO 2 Hollow Spheres by UV Light Illumination.

In this paper, a facile and elegant Green Chemistry method for the synthesis of SnO based hollow spheres has been investigated. The influences of doping, crystallite morphology, and operating condition on the O sensing performances of SnO based hollow-sphere sensors were comprehensively studied. It was indicated that, compared with undoped SnO, 10 at. % LaOCl-doped SnO possessed better O 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 sensing properties of the 10 at. % LaOCl-SnO sensor were significantly improved by ultraviolet light illumination, which was suited for room-temperature O sensing applications. Besides, this sensor also had a better selectivity to O with respect to H, CH, NH, and CO. The remarkable increase of O 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 response. On the other hand, UV light activates desorption of oxygen adsorbates when exposed to pure N, contributing to rapid response/recovery speed. The results demonstrate a promising approach for room-temperature O detection.