Microwave-assisted hydrothermal synthesis of ZnO rod-assembled microspheres and their photocatalytic performances

ZnO rod-assembled microspheres were successfully fabricated by using the microwave-assisted hydrothermal method in the existence of the poly ethylene glycol (PEG) with the molecular weight of 2000. The structure and morphology of as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The experimental results exhibit that the as-prepared ZnO microspheres with a diameter about 1.5-2.0 mu m were composed of many rods with the diameter of 300 nm and the length of 1 mu m, respectively. Photoluminescene measurement shows a broad visible emission band centered at around 500-560 nm. The improved catalytic activity may be attributed to structural difference, including morphology, surface orientation and surface defects. Furthermore, the possible growth and photodegradation mechanism of the as-prepared sample is also briefly discussed. (C) 2010 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.