One step synthesis of branched SnO2/ZnO heterostructures and their enhanced gas-sensing properties

In this work, a novel branched heterostructural composite composed of nanorods ZnO backbone and SnO2 branches was prepared via a facile one-step hydrothermal method. The morphology, structure and component of the SnO2/ZnO composite was characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and elemental mapping analysis. The evolution process of the SnO2/ZnO composite was observed by SEM that the SnO2 branches gradually grow on ZnO backbones. The composite with novel heterostructure was applied as the sensing material for the fabrication of gas sensor, and their gas sensing properties were tested for response to various gases. Compared to pure ZnO gas sensors the branched SnO2/ZnO gas sensor exhibited enhanced gas sensing properties toward ethanol, giving a response of 18.1-100 ppm.