Controllable synthesis of hierarchical ZnO microstructures via a hydrothermal route

Hierarchical ZnO superstructures assembled by ZnO nanorods have been successfully constructed in mixed solvents of ethylene glycol (EG)–water via a facile hydrothermal method. ZnO nanostructures with dumb-bell-like and microsphere morphologies were obtained by only a change of the precursor concentration. The products were characterised by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Raman scattering and room-temperature photoluminescence spectra. The possible formation mechanism of these hierarchical ZnO nanostructures is also proposed.