Fabrication of octahedral-shaped polyol-based zinc alkoxide particles and their conversion to octahedral polycrystalline ZnO or single-crystal ZnO nanoparticles

An ultrasonically assisted two-step polyol process was established to prepare a novel ethylene glycol-based zinc alkoxide with octahedral morphology. The octahedral-shaped zinc alkoxide particles could be converted to ZnO by heating to 350 °C or above, without altering the octahedral shape. Interestingly, when exposed to atmospheric moisture at room temperature for more than 48 h, the octahedral zinc alkoxide was in situ transformed to single-crystal ZnO nanoparticles via hydrolysis in the octahedral configuration, accompanied by release of ethylene glycol. The morphology, composition, and phase structure of the glycol-based zinc alkoxide and the resulting products, i.e., octahedral ZnO polycrystalline particles and single-crystal ZnO nanoparticles, were characterized by means of scanning electron microscopy (SEM), Fourier transformation infrared spectrometry (FTIR), X-ray diffraction (XRD), thermal analysis (TA), elemental analysis (EA), and transmission electron microscopy (TEM). The present approach for octahedral polycrystalline ZnO or spherical single-crystal ZnO nanoparticles would provide a potential facile route to fabricating other metal oxides with controllable morphology. The hydrolysis of the octahedral zinc alkoxide might be used to facilitate slow release of ethylene glycol, a common compound for lowering freezing point.