Sulfur dioxide gas sensing at room temperature based on tin selenium/tin dioxide hybrid prepared via hydrothermal and surface oxidation treatment
Qiannan Pan, Zhimin Yang, Weiwei Wang, Dongzhi Zhang
Abstract
Abstract In this paper, a novel SnSe/SnO 2 nanoparticles (NPs) composite has been successfully fabricated through hydrothermal method and surface oxidation treatment. The as‐prepared sample was characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). A series of morphological and structural characteristics confirm that the SnSe/SnO 2 NPs composite shows a core–shell structure with a SnO 2 shell with thickness of 6 nm. The prepared SnO 2 NPs and SnSe/SnO 2 NPs composite were applied as gas‐sensing materials, and their gas‐sensing properties were investigated at room temperature systematically. Experimental results show that the response value of the SnSe/SnO 2 composite sensor toward 100 × 10 –6 SO 2 is 15.15%, which is 1.32 times higher than that of pristine SnSe (11.43%). And the SnSe/SnO 2 composite sensor also has a detection limit as low as 74 × 10 –9 and an ultra‐fast response speed. The enhanced gas‐sensing performance is attributed to the formation of p–n heterojunction between SnSe and SnO 2 and the appropriate SnO 2 shell thickness.