Hydrothermal synthesis of Hydrangea macrophylla-like Ce-doped SnO2 microspheres and their enhanced sensing properties

Abstract

The hydrangea macrophylla-like SnO2 microspheres doped with different Ce contents (0, 2, 6 and 10 mol%) were synthesized by a facile hydrothermal method. The crystal phase, micro morphology and element composites were investigated by x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) with energy-dispersive spectroscopy (EDS) and x-ray photoelectric spectroscopy (XPS). The results demonstrated the hydrangea macrophylla-like microstructure of the prepared samples and the existence of Ce3+/Ce4+ when doped with Ce element. Furthermore, the synthesized Ce-doped SnO2 samples’ sensing properties were investigated. The SnO2 microspheres doped with 6 mol% showed the largest response to acetone during 0.2–20 ppm at 320 °C as well as good selectivity and reproducibility. As discussed, the Ce doping that generates n-n type heterojunction and the Ce3+/Ce4+ conversion increases the resistance change of Ce-doped SnO2 in reducing atmosphere and enhances the response.