Preparation And Properties Of Graphene Hybrid Nanomaterials

With the rapid development of nanotechnology, hybrid nanomaterials that possess unique properties from their components, have received great interests of research. For instance, carbon nanomaterials especially graphene-based nanomaterials, due to its extraordinary electronic, thermal and mechanical properties, hold great promise for potential applications in many technological fields such as advanced polymers, heterogeneous catalyzers, biosensors, hydrogen storage, etc. In this paper, hybrid nanomaterials based on graphene were designed and fabricated, and their properties and promising applications were studied primarily. The detail research contents and results are summarized as follows:1. Fast synthesis of graphene oxide based polyacrylonitrile (GO/PAN) hybrid nanofibers using electrospinning technologyIn the study of graphene-polymer hybrid nanomaterials, based on the electrospinning technology, we reported a simple and fast new approach to the synthesis of graphene oxide/polyacrylonitrile (GO/PAN) hybrid nanofibers. In these nanofibers, GO sheets were entirely wrapped inside the nanofibers, and rolled into nanotubes. The results of thermogravimetric analysis (TGA) showed that hybrid nanofibers possessed enhanced thermal stability compared to pure PAN nanofibers. Moreover, the solubility of these hybrid nanofibers in original solvent (DMF) was greatly decreased due to the strong interaction between GO and PAN. In addition, the GO/PAN hybrid nanofibers can be further reduced into graphene/PAN nanofibers using hydrazine hydrate as reducer. This method can effectively avoid aggregation of graphene in the nanofibers and make sure of its dispersion in the nanofibers. Thus, it provided a feasible approach to the synthesis of graphene-based hybrid nanofibers.1. Synthesis of graphene composite decorated with highly dispersed gold nanoparticles (Au-GOSH)In the study of graphene-nanoparticles hybrid nanomaterials, we introduced a two-step approach to synthesize gold nanoparticles-graphene (Au-GOSH) hybrid nanomaterials based on functionalized graphene oxide with mercapto groups. In these Au-GOSH nanomaterials, Au nanoparticles (AuNPs) were evenly decorated on the surfaces of mercapto graphene oxide without aggregation. Moreover, the average diameter of the AuNPs was3nm, which was the same as that before immobilization onto graphene nanosheets. This method can easily control the size, morphology and decorating density of nanoparticles. Electrochemical study demonstrated that the Au-GOSH hybrid nanomaterials had better catalytic activity towards oxygen reduction in alkaline medium, compared to AuNPs and graphene. The electrocatalytic process is a two-electon, two-step pathway for ORR based on RDE tests.