Porous spheres-like ZnO nanostructure as sensitive gas sensors for acetone detection

Porous spheres-like zinc oxide (ZnO) nanostructure was synthesized by electrospinning method followed by calcining. The microstructure and chemical composition were investigated with X-ray diffraction, energy dispersive spectroscopy, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmet–Teller method and X-ray photoelectron spectroscopy. The results showed that the porous spheres-like ZnO nanostructure with large specific surface area (22.6 m2/g) was composed of ZnO nanoparticles of ∼40–80 nm grain size and numerous oxygen species (O− and O2−) were adsorbed on the surface of ZnO nanoparticles. Meanwhile, the testing on gas sensing performance revealed that porous spheres-like ZnO nanostructure based sensor has an optimum operating temperature of 310 °C, large resistance (1064 kΩ), good stability for low concentration acetone (2 ppm acetone at 310 °C) and good selectivity at 310 °C for acetone.

► Porous spheres-like ZnO nanostructure was composed of nanoparticles.
► ZnO nanostructure has a large specific surface area of 22.6 m2/g.
► ZnO based sensor can detect 2 ppm acetone at 310 °C.
► Sensor has good stability for 2 ppm acetone at 310 °C.