Preparation, characterization and acetone sensing properties of Ce-doped SnO2 hollow spheres

The Ce-doped SnO2 hollow spheres were prepared by the uniform coating of Ce and Sn precursors onto polystyrene (PS) spheres, following by heat treatment at 550 °C to remove the PS spheres core. The observations of field emission gun scanning electron microscope (FESEM) and transmission electron microscopy (TEM) showed that Ce-doped SnO2 hollow spheres with a shell thickness of ∼200 nm, which were composed of nanoparticle aggregates with the crystallite size of 10–15 nm. X-ray diffraction (XRD) exhibited that all the diffraction peaks have been indexed to a rutile structure of SnO2. No diffraction peaks of cerium oxide were observed, suggesting that Ce4+ ions get uniformly substituted into the Sn4+ sites or interstitial sites in SnO2 lattice. The Ce-doped SnO2 hollow spheres showed perfect sensing performance toward acetone gas with rapid response, good stability and high response at 250 °C compared with pure SnO2 hollow spheres.