A novel synthesis and excellent photodegradation of flower-like ZnO hierarchical microspheres

We demonstrate an easy, novel synthesis of nanosheet-based flower-like ZnO microspheres without any catalyst and template. The layered hydroxide zinc acetate Zn₅(OH)₈(CH₃COO)₂· 2H₂O (LHZA) nanostructures, one of important and efficient precursors to synthesize three dimensional (3D) ZnO hierarchical microstructures, are first fabricated in aqueous solution at room temperature. The detailed crystal structure and formation mechanism of the LHZA are also investigated. It is noteworthy that the initial ZnO seed layer is crucial to the growth of the final nano/microarchitectures. We found that the as-synthesized hierarchical ZnO microspheres obtained from the decomposition of LHZA showed excellent photocatalytic activity for the photodegradation of rhodamine 6G. This facile, efficient, and economical work provides a new route to simply and mildly synthesize ZnO 3D hierarchical microspheres, which may be adopted to prepare other metal oxide microstructures.