Hydrothermal synthesis of hollow twinning ZnO microstructures

Two kinds of hollow twinning ZnO microstructures were synthesized through a simple hydrothermal method without additional templates or any surfactants. Dumbbell-like and shuttle-like ZnO microstructures with hollows were obtained by changing the materials source. The products were characterized by X-ray power diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). It was found that different precursors may be responsible for the formation of two different morphologies. Based on the time-dependent experiments, we investigated the growth process of these hollow twinning structures and found the "Ostwald-ripening process" played an important role. The interesting point of this growth process was that the interface of the two twinning structure performed as the activate center where the Ostwald-ripening process carried out. We also investigated the luminescent properties of the as-obtained products by photoluminescence (PL) spectroscopy. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim