Construction of PdO-decorated double-shell ZnSnO3 hollow microspheres for n-propanol detection at low temperature

As a unique class of multifunctional nanostructures, hollow multi-shelled structures have attracted great interest due to their structural advantages. Herein, pure and PdO-loaded double-shell ZnSnO3 hollow microspheres have been synthesized by a facile co-precipitation method and subsequent calcination treatment. The structure and morphology of the as-obtained samples are characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The gas sensing properties of the sensors based on pure and PdO-loaded double-shell ZnSnO3 hollow microspheres are systematically analyzed. The results show that the sensor based on 4 wt% PdO-loaded double-shell ZnSnO3 hollow microspheres not only shows high responses (30.8) and rapid response and recovery speed (1 s and 25 s) to 100 ppm n-propanol at a low working temperature of 140 °C, but also exhibits good repeatability and long-term stability. The excellent n-propanol sensing performance is mainly attributed to the formation of the unique double-shell structure as well as the catalytic and sensing effect of PdO.