Fabrication of 1D Zn2SnO4 nanowire and 2D ZnO nanosheet hybrid hierarchical structures for use in triethylamine gas sensors

Abstract

Abstract In this work, unique Zn2SnO4–ZnO hierarchical structures composed of one-dimensional Zn2SnO4 nanowires and two-dimensional ZnO nanosheets were successfully synthesized via a facile hydrothermal method combined with calcination. The Zn2SnO4 nanowires bridged across the ZnO nanosheets, which played an important role in electron transmission. Compared with pure Zn2SnO4 nanowires and pure ZnO nanosheets, the obtained Zn2SnO4–ZnO hierarchical structures exhibited improved gas-sensing performance toward triethylamine (TEA) in terms of a low operating temperature, high sensor response, and good selectivity. Gas-sensing test results revealed that the sensor response of Zn2SnO4–ZnO sensor reached 175.5 toward 100\u202fppm TEA at an optimum operating temperature of 200\u202f°C, which is approximately 47.4 and 30.8 times higher than that of pure Zn2SnO4 and pure ZnO, respectively. In addition, the Zn2SnO4–ZnO hierarchical structures exhibited good selectivity and long-term stability to TEA, suggesting their potential application in advanced TEA gas sensors. The improved sensing properties of the Zn2SnO4–ZnO hierarchical structure could mainly be attributed to their large specific surface areas, unique bridged hierarchical microstructure, and appropriate energy band structure.