Synthesis of three-dimensional flower-like hierarchical ZnO nanostructure and its enhanced acetone gas sensing properties

•A flower-like hierarchical ZnO nanostructure was prepared via hydrothermal method.•The as-prepared ZnO exhibits superior acetone gas sensing properties.•The enhanced performance derives from the geometric, crystal and surface structure.

A three-dimensional (3D) flower-like hierarchical ZnO nanostructure was successfully synthesized via a facile and efficient hydrothermal method. The sample was characterized by XRD, FESEM, Raman, UV–vis DRS and Photoluminescence (PL) techniques. The XRD pattern revealed that the sample was well-crystallized in a hexagonal wurtzite structure. FESEM images showed that the as-prepared ZnO exhibited a nanosheet-assembled hierarchical flower-like ZnO nanostructure, which was self-assembled by thin and uniform nanosheets with a thickness of approximately 30 nm. Raman spectra exhibited that the sample kept the crystal structure of the bulk ZnO and possessed more surface defects. UV–vis spectra showed that a significant blue-shift in the absorption edge for the as-prepared ZnO as compared to the commercial ZnO. PL spectra indicated that the concentration of surface oxygen vacancies in the as-prepared ZnO was much higher than that of the commercial ZnO. Furthermore, the nanosheet-assembled flower-like ZnO nanostructure exhibited excellent gas sensing properties towards acetone, indicating that the as-prepared ZnO architecture is a promising material for gas sensors.

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