Oxygen vacancy-based Tb-doped SnO2 nanotubes as an ultra-sensitive sensor for ethanol detection

Abstract

In this work, different concentrations of terbium (Tb) doped SnO2 nanotubes (NTs) were synthesized via simple uniaxial electros-pinning and high-temperature calcination. The mapping results show that Tb elements are uniformly distributed on SnO2 NTs. X-ray photoelectron spectroscopy (XPS) was used to characterize the changes of oxygen ion species of pristine SnO2 and 7 mol% Tb-doped SnO2. In terms of gas sensitive performance, the sensor prepared by this method has low operating temperature, excellent selectivity and ultra-high sensitivity. Notably, compared with other obtained SnO2 samples, the 7 mol% NTs presented the best sensing performance, and the response to 100 ppm ethanol reached 53.6 at 200 °C. Combined with the study of gas sensitivity, it can be confirmed that doping Tb increases the number of active sites (such as oxygen vacancies (VO)) on the surface of SnO2, thus enhancing the gas sensitivity and electrical responsiveness of SnO2. Hence, the research in this work will be helpful to the development of new high performance gas sensors based on dopant metal oxide semiconductor.