Hydrothermal preparation and gas sensing properties of Zn-doped SnO2 hierarchical architectures

A one-step hydrothermal route was used to synthesize undoped and Zn-doped SnO2 hierarchical architectures. The morphologies and structures of the as-prepared samples were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The results clearly revealed that the as-prepared SnO2 hierarchical architectures were composed of many 2 dimensional (2D) nanosheets with the thickness of about 30 nm. The gas sensing properties of the as-prepared undoped and Zn-doped SnO2 samples were tested toward various gases. The sensor based on S3 (Zn2+/Sn4+ = 0.056) showed excellent selectivity toward ethanol at the operating temperature 213 °C, giving a response of about 14.4 to 100 ppm, which was about 3.2 times higher than that of sensor based on pure SnO2.