Monodispersed hollow microsphere of ZnO mesoporous nanopieces: Preparation, growth mechanism and photocatalytic performance

The mesoporous ZnO nanopieces-based nest-like hollow microsphere are successfully synthesized through the thermal decomposition of hydrozincite (Zn5(CO3)2(OH)6) formed by a facile hydrothermal method. The time-dependent experiments reveal the unique growth process of hydrozincite (Zn5(CO3)2(OH)6) microsphere. Hydrozincite Zn5(CO3)2(OH)6 nanopiece clusters were formed via homogenous nucleation process at the initial stage, these hydrozincite nanopieces assemble into the ring-like structures through a complex secondary nucleation with the growth of Zn5(CO3)2(OH)6 crystalline at the edge of each nanopiece, and further formed the hollow microspheres. Study show ZnO inherits well the size and morphology of hydrozincite crystals after the thermal decomposition. Nest-like hollow microspheres of ZnO mesoporous nanopieces are monodispersed with a uniform size distribution of ∼15 μm. Study also shows ZnO nanopieces interwaved microspheres with high surface area and porosity exhibit excellent photocatalytic activitiy on the photodegradation of methyl orange.