Synthesis and characterization of monodisperse hollow SnO2 microspheres and their enhanced sensing properties to ethanol

The monodisperse hollow SnO2 (H-SnO2) microspheres were successfully synthesized by the ion exchange method using sulfonated PS microspheres as a template. The structure and morphology were characterized by X-ray diffraction, transmission electron microscopy and high-resolution transmission electron microscopy, which confirms the hollow structure of the products. The H-SnO2 microspheres are composed of numerous SnO2 nanoparticles with a shell thickness of about 13 nm. The monodisperse H-SnO2 microspheres have a high specific surface area of 55.54 m2/g, which improves the gas sensing properties toward ethanol. Gas-sensing measurement results indicate that H-SnO2 microspheres exhibit an excellent sensitivity (103.1) toward 200 ppm ethanol at 260 °C, which is much higher than that (65.8) of SnO2 nanoparticles.