Facile Solution Synthesis and Characterization of ZnO Mesocrystals and Ultralong Nanowires from Layered Basic Zinc Salt Precursor

Novel hierarchical ZnO mesocrystals and ultralong ZnO nanowires have been prepared from a precursor of synthetic layered basic zinc acetate nanobelts by a facile solution route in the presence of poly(vinyl pyrrolidone) (PVP). X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM) were used to characterize the products. Refluxing an aqueous dispersion of the nanobelts precursor in the presence of PVP at 100 °C for 6 h leads to the formation of well-defined hierarchical ZnO bundled mesocrystals. With an increase in the basicity of the reaction solution, ultralong ZnO nanowires were prepared. On the basis of the experimental results, a mechanism involving the self-organization of smaller inorganic building blocks during the crystallization of ZnO crystals was proposed. It has been demonstrated that PVP plays a key role in the formation of such novel hierarchical mesocrystals. Photoluminescence results show that the as-synthesized ZnO bundled mesocrystals have a broad yellow emission at above 568 nm excited by UV light, and this yellow emission band is attributed to a singly charged oxygen vacancy or other defects. Our work may shed some light on the design of other well-defined complex superstructures, and the as-grown architectures may have potential applications.