Acetone sensing characteristics of ZnO hollow spheres prepared by one-pot hydrothermal reaction

Abstract ZnO hollow spheres were one-pot fabricated by hydrothermal treatment. Zinc nitrate were dissolved together with urea and glucose in water, and the mixtures were heated at 180 °C for 24 h. During the hydrothermal treatment, carbon spheres are formed with zinc ions incorporated into the hydrophilic shell. The removal of carbon via calcinations yields hollow zinc oxide spheres. The as-prepared samples were characterized by X-ray diffraction and the field emission gun scanning electron microscope. The results indicated that the products were pure hexagonal ZnO with the structure of hollow sphere, and the formation mechanism of ZnO hollow spheres was discussed. Consequently, the ZnO hollow spheres exhibited good sensing performance towards acetone gas with rapid response when operated at 300 °C.