Synthesis And Electrochemical Properties Of Graphene-based Hybrid Nanomaterials

With the development of nanotechnology, nanomaterial composed of only onecomponent has not been suitable for the development of science and technology,meaning seeking and designing hybrid nanomaterials with more excellent propertieswould be the trend of nanomaterials development. Hybrid nanomaterials not only ownthe basic properties of nanomaterials, but also exhibit composite synergisticmultifunctional effects. Besides that, the surface properties of the nanomaterials arealso changed, and the hybrid nanomateirals often exhibit excellent properties byeffectively enlarging the specific surface area of the different components.Graphene-based hybrid nanomaterials have been received a great much attentiondue to its prominent properties and potential applications in electrochemical sensing,storage and catalysis. The key part of synthesizing and assembling graphene-basedhybrid nanomaterial is the selection of the linker. At present, most researchersemployed conductive polymer as the linker, obtaining the graphene-based hybridnanomaterial via the electrostatic interaction. The dissertation mainly focused ondeveloping highly conductive graphene-based nanomaterial functionalized withoutconductive polymer, and investigating the corresponding electrochemical properties.1. We synthesized graphene-silver nanocomposite film via electrochemicalmethods directly from graphene oxide and silver nitrate. Several characterizationssuch as AFM, TEM, SEM, XPS and EDX were employed to investigate the product,and it was proved to be a hybrid nanomaterial composed of graphene-based silvernanoparticles. The obtained hybrid nanomaterial was found to exhibit characteristicelectrochemical response towards the reduction of hydrogen peroxide, indicating thematerial can be applied as hydrogen peroxide electrochemical sensing. Theelectrochemical results showed that the determination of the hybrid nanomaterialtowards hydrogen peroxide reduction is fast, accurate and the theoretical detectionlimit is1.6μM. Besides that, the analysis of real samples has also been carried out indiluted fetal bovine serum aqueous solution, and the results showed the prominent electrochemical properties of hybrid nanomaterials.2. We employed DMF as reductant agent to reduce graphene oxide, maintainingthe stability of graphene without using conductive polymer as the linker. At the sametime, we synthesized single-crystallined platinum nanoflowers in the presence ofpotassium iodide and polyvinylpyrrolidone while using ethylene glycol as reductantagent, and platinum polyhedron nanostructure while using potassium bromide. Bysimply mixing the platinum nanomaterial and DMF-reduced graphene, thegraphene-based platinum hybrid nanomaterials can be obtained. The successfulcombination of the two components can be proved by several characterizations suchas TEM and XPS. The hybrid nanomaterials were applied as cathode and anodecatalysts for direct methanol fuel cell, and showed excellent catalysis properties,indicating the hybrid nanomaterials would be suitable as an electrocatalysis material.3. We prepared graphene-manganese oxide hybrid nanomaterial by simplymixing and heating DMF-reduced graphene and potassium hypermanganate mixedsolution. The characterizations such as AFM, TEM and XPS proved the combinationof the two components. The electrochemical storage properties of the hybridnanostructure as supercapacitor material were examined employing sodium sulfate aselectrolyte. The electrochemical results showed that the hybrid nanomaterial exhibitwell-performed activities and might be further used as electrode materials forsupercapacitor.