The Preparation And Photocatalytic Properties Of Multiple Morphology ZnO And ZnO/graphene Nanomaterials

ZnO which is an important kind of wide-band-gap semiconductor exhibits manyexcellent properties in optical, electrical, chemical and biological aspects. However,the active is not very well when it was used as photocatalytic materials. In this paper,we prepared different morphology of ZnO nanomaterials and ZnO/graphenecomposites to improve its photocatalytic performance.Firstly, we prepared ZnO by hydrothermal method through orthogonalexperiment system. We learn that the reaction temperature, reaction time, pH valueand concentration of reactants are the mainly factors that influence the morphology.We can get three different morphologys of ZnO (ZnO nanospheres, ZnO nanorodsand ZnO nanoflowers) by changing these experimental factors. The optimalexperimental conditions for preparing Zinc Oxide nanorods by hydrothermal are that180℃,10h and the pH is11. Apart from this, we also get Zinc Oxide nanospheresby sol gel method.Four different morphologys of Zinc Oxide were analyzed by XRD, SEM,UV-Vis and FS for studying the structure, morphology and properties. We evaluatethe photocatalytic activity of the four different morphologys of ZnO by themethylene blue decolorization rate. We can know that, in terms of degradating themethylene blue, Zinc Oxide nanospheres are the lowest, while the Zinc Oxidenanoflowers are the strongest of four different morphologys. We also analyze themechanism of this phenomenon.In this dissertation, through the Hummers method prepared the graphene. Theprepared samples were characterized by XRD, TEM, IR and Raman spectroscopy.By comparing the graphene and graphene oxide, we can know that the expandedgraphite after deep oxidation and reduction can obtain thinner layer graphene.The ZnO/graphene composites were prepared by ultrasound method. Theprepared samples were characterized by XRD, TEM, and IR to study the structure,morphology and properties. It is concluded that Zinc Oxide and graphene have strong attractive interaction. After photocatalytic activity test, we can find that thephotocatalytic activity of ZnO/graphene (60.3%) improved more than4timescompared with pure Zinc Oxide (14.7%). It is mainly due to graphene play the therole of electron transfer in the composites. When the percentage of grapheme is up to15%, the photocatalytic activity of ZnO/graphene composites is strongest.