Enhanced Gas Sensing Properties of SnO₂ Hollow Spheres Decorated with CeO₂ Nanoparticles Heterostructure Composite Materials

Abstract

CeO₂ decorated SnO₂ hollow spheres were successfully synthesized via a two-step hydrothermal strategy. The morphology and structures of as-obtained CeO₂/SnO₂ composites were analyzed by various kinds of techniques. The SnO₂ hollow spheres with uniform size around 300 nm were self-assembled with SnO₂ nanoparticles and were hollow with a diameter of about 100 nm. The CeO₂ nanoparticles on the surface of SnO₂ hollow spheres could be clearly observed. X-ray photoelectron spectroscopy results confirmed the existence of Ce³⁺ and the increased amount of both chemisorbed oxygen and oxygen vacancy after the CeO₂ decorated. Compared with pure SnO₂ hollow spheres, such composites revealed excellent enhanced sensing properties to ethanol. When the ethanol concentration was 100 ppm, the sensitivity of the CeO₂/SnO₂ composites was 37, which was 2.65-times higher than that of the primary SnO₂ hollow spheres. The sensing mechanism of the enhanced gas sensing properties was also discussed