Laser-engineered oxygen vacancies for improving the NO2 sensing performance of SnO2 nanowires

Methods for oxygen vacancy engineering usually require high-temperature heating processes, which are substantially time-consuming. Laser irradiation techniques are a viable alternative to conventional methods, as they enable room-temperature tuning of material functionality using a simple, swift, and inexpensive process. In this report, the effects of pulsed laser irradiation on the formation of oxygen vacancies and its positive relationship with the sensing performance of SnO2 have been investigated. Based on density functional theory calculations, we suggest that the formation of laser-induced bridging oxygen defects and the resulting excess electrons on the SnO2 surface change the surface orbital structures of the Sn atoms in a manner favorable for NO2 adsorption, thus playing a key role in improving its sensing performance.