Preparation And Properties Of Graphene And ZnO/Graphene Hybride Structures

Graphene has become the research focus due to its high surface area, good electric and mechanical properties, and graphene based metal-oxide nanocomposites have received wide attentions because of enormous potential applications in many fields.In this thesis graphene film is fistly grown on copper and then three-dimensional (3D) graphene foam is prepared on nickel foam by chemical vapor deposition method. Well-aligned ZnO nanorod arrays are prepared by seed-mediated hydrothermal growth in aqueous solution. Based on the preparation of ZnO nanorods,3D graphene is combined with ZnO nanorods by in situ hydrothermal method.3D graphene foams are characterized with SEM、TEM and Raman and so one. Ultraviolet-visible light absorptivity, photoluminescence property and hydrophobicity of ZnO nanorods prepared with different growth time are also studied, and thus the optimum parameter of ZnO nanorods synthesized by hydrothermal method is also determined. On the basis of the selected optimum parameter, the effect of growth solution concentration on morphology and electrochemical performances of the composites is researched. The main results are as follows:Prepare graphene film by atmospheric chemical vapor deposition method, in given conditions of growth time=10 mins, cooling rate=20 ℃/mins, the main parameter that affect the growth of graphene film:ratio of methane to hydrogen is systematically studied, and it’s found that the overall performances of graphene under the preparation condition with C=2 sccm:20 can are the best.Prepare three-dimensional graphene on the nickel foam by atmospheric chemical vapor deposition method, and transfer 3D graphene from nickel foam. The 3D graphene possesses three-dimensional interconnected graphene networks structure and its pore size is about 400 μm.Prepare ZnO nanorods by seed-mediated hydrothermal method, the size distribution is uniform, the ZnO nanorods are about 50 nm in diameters and 530 nm in length. The effect of growth time on the ultraviolet absorption, photoluminescence performances and hydrophobicity properties of ZnO nanorods is studied. Finally well-aligned ZnO nanorods with good crystallinity are successfully prepared.Integrate 3D graphene with ZnO nanorods by in situ hydrothermal method, and the electrochemical performances of the hybride structure are studied. It is found that the hybride structure (Zn2+=0.025M) exhibits high sensitivity for detection of hydrogen peroxide (H2O2) with the extrapolated lower detection limits of 10 μM, linear detection range from 10 uM to 160 μM(R2=0.99501) and response time of 3s, compared to single three-dimensional graphene foam, the performances of hybride structure are greatly improved and are promising for electrochemical sensors fields.