Preparation and characterization of uniform circinate aggregates of sheet ZnO nanoparticles

Uniform circinate aggregates of sheet ZnO nanoparticles with a specific surface area of 24 m2.g−1 were prepared by the direct precipitation method. The circinate aggregates were hexagonal ZnO, with the wall thickness ranging from 0.5 to 1 μm and the diameter ranging from 5 to 10 μm. The backs of the circinate aggregates were regularly arranged by numerous sheet ZnO nanoparticles with a thickness of 30-80 nm and a diameter of 300-400 nm. The precursors were aggregates of sheet Zn5(CO3)2(OH)6 nanoparticles, which were decomposed into ZnO by calcining in air in the range of 200-285°C, and the ZnO retained the similar special structure. The C2H5OH content had a significant effect on the formation of sheet ZnO. The centripetal force, the Van der Waals force, and the hydrogen bond were deduced as the driving forces of the formation of circinate.