Synthesis of novel SnO2/ZnSnO3 core–shell microspheres and their gas sensing properities

Large-scale novel core–shell structural SnO2/ZnSnO3 microspheres were successfully synthesized by a simple hydrothermal method with the help of the surfactant poly(vinyl pyrrolidone) PVP. The as-synthesized samples were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The results indicate that the shell was formed by single crystalline ZnSnO3 nanorods and the core was formed by aggregated SnO2 nanoparticles. The effects of PVP and hydrothermal time on the morphology of SnO2/ZnSnO3 were investigated. A possible formation mechanism of these hierarchical structures was discussed. Moreover, the sensor performance of the prepared core–shell SnO2/ZnSnO3 nanostructures to ethanol was studied. The results indicate that the as-synthesized samples exhibited high response and quick response-recovery to ethanol.