화학공학소재연구정보센터
Materials Research Bulletin, Vol.48, No.6, 2375-2382, 2013
Hydrothermal synthesis of coral-like Au/ZnO catalyst and photocatalytic degradation of Orange II dye
A porous coral-like zinc oxide (c-ZnO) photocatalyst was synthesized by the hydrothermal method. The coral-like structure was obtained by precipitating Zn-4(CO3)(OH)(6)center dot H2O (ZnCH), which forms nanosheets that aggregate together to form microspheres with the coral-like structure. X-ray diffraction (XRD) studies indicate that after heating at 550 degrees C the ZnCH microspheres can be converted to ZnO microspheres with a morphology similar to that of ZnCH microspheres. Thermogravimetric analysis (TGA) shows this conversion takes place at approximately 260 degrees C. A simple electrostatic self-assembly method has been employed to uniformly disperse Au nanoparticles (1 wt.%) on the ZnO surface. In this procedure beta-D-glucose was used to stabilize the Au nanoparticles. Scanning electron microscope images indicate that the diameter of coral-like ZnO microspheres (c-ZnO) is about 8 mu m. X-ray diffraction reveals that the ZnO is highly crystalline with a wurtzite structure and the Au metallic particles have an average size of about 13 nm. X-ray photoelectron spectroscopic (XPS) studies have confirmed the presence of ZnO and also showed that the Au is present in the metallic state. The photocatalytic degradation of Orange II dye, with either ultraviolet or visible light, is faster on Au/c-ZnO than on c-ZnO. (C) 2013 Elsevier Ltd. All rights reserved.