Fabrication of Pr-doped SnO2 spherical core-shell nanostructure with wrinkly shell and the gas sensing properties

Pr-doped SnO2 spherical core-shell nanostructure with walnut-like wrinkly shell was synthesized by using carbon microspheres as templates. The crystallization characteristics and morphology were investigated. The diameter of walnut-like Pr-doped SnO2 spheres is about 250 nm, and the wrinkled surfaces with high specific surface area may increase the contact area between analytes and chemisorbed oxygen species, and is helpful to the fast response. Pr-doped SnO2 sensor was prepared, the gas sensing analyses indicate that the sensor exhibits excellent gas sensing performance to ethanol at 200 °C. The response to 200 ppm ethanol is up to 124, in addition to the good selectivity. The remarkable improvement in gas sensing properties may be attributed to the unique core-shell nanostructure with walnut-like wrinkly shell and the Pr doping. The possible growth mechanism and the ethanol sensing mechanism of the core-shell Pr-doped SnO2 are also discussed.