Hydrothermal synthesis of sno2 nanoneedle-anchored nio microsphere and its gas sensing performances

Abstract

In this study, we reported a successful synthesis of a nanocomposite based on SnO2 nanoneedles anchored to NiO microsphere by a simple two-step hydrothermal route. The results show that the SnO2/NiOnanocomposite-based sensor exhibits more prominent performances than the pristine NiO microsphere to NO2 such as larger responses andmore outstanding repeatability. The improved properties are mainly attributed to the p-n heterojunctions formed at the SnO2-NiO interface,leading to the change of potential barrier height and the enlargement of the depletion layer. Besides, the novel and unique nanostructureprovides large and effective areas for thesurface reaction. In addition, a plausible growth mechanism and the enhanced sensing mechanism were proposed to further discuss the special nanostructure which willbenefit the exploration of high-performance sensors.