A Study On Controlled Synthesis And Property Of Graphene-based Series Of Copper Nanoparticles Functional Composites

Graphene, a monolayer of carbon atoms packed into a dense honeycomb crystalstructure. So far,it is the only two—dimensionalfree atom crystal, which is not onlythe basic structural units to constructthe zero-dimensional fullerenes, one-dimensionalcarbon nanotubes, three—dimensional body graphene. Grpahene, because of theuniqueelectronic, thermal, optical and mechanical properties, has attractedtremendous attentionfromboth the experimental and theoretical scientific communities.Nanoparties have aroused enormous attention due to their excellent properties. Thenanocomposites based on graphene are emerging as a class of exciting materials thathold promise for many applications. Graphene based materials have shown promisingapplications in electronics, optics, magnetics, biomedicine, catalysis, sensors, energystorage etc. In this dissertation, the graphene and graphene oxide were used asprecursor to prepare graphene based composite, the properties of these products werealso analyzed. Furthermore, the synthesis method of this kind of compound and themorphological control were also investigated. The dissertationis mainly focusedon:（1） In situ reduction method to prepare Gs/Cu composite materialsUsing graphite oxide as initial raw materials, and joining CuSO₄as precursor,due to the electrostatic adsorption, copper ions adsorp on the surface of graphite oxide,then Gs/Cu nanocomposite materials were synthesized by in situ reduction methodwith Vc as reducing agent. And the XRD results show that the graphene/Cunanoparticles were prepared successfully. Through compared with the FTIR spectra ofgraphite and graphene oxide, showed that there are chemical bonds cooperationbetween graphene with copper nanoparticles, rather than a physical adsorption. UsingSEM and TEM to observe the microstructure of composite materials, coppernanoparticles evenly coated on the surface of graphene sheet. In addition, compositematerial has good conductive properties and thermal stability properties.（2） The Gs/Cu/PMMA films were synthesized by in situ polymerizationThe Gs/Cu nanocomposites were dispersed in the monomer MMA, ultrasonicdispersion evenly, and joining the in-situ polymerization initiator BPO directly,Gs/Cu/PMMA composite membrane materials were prepared successfully, theprepared thin film material, has good mechanical properties and thermal stability properties, showing promising applications in the electromagnetic shielding materials,conductive flexible thin film materials.（3） Preparation of Gs/L₁and GNS/L₂by non-covalent modify graphene throughstrong π-π conconjugate actionsIn this experiment, Cu（Ⅱ）-1,10phenanthroline complexes1（L₁） andCu（Ⅱ）-1,10phenanthroline2（L₂） non-covalent modify graphene and GNS. Gs/L₁and GNS/L₂were prepared via strong π-π conconjugate actions. By FTIR spectrumanalysis, ultraviolet spectrum, Raman analysis proved that complexes L₁, L₂andGs/L₁, GNS/L₂composite materials were prepared successfully;the microstructure ofthese composites were observed by scanning electron microscopy （SEM） analysis, thecomposite material has excellent thermal stability and optical performance, showingpromising applications in photoelectric conversion material. And then discusses theinfluence of the different graphite conjugated system and adjacent phenanthrolinecopper complexes on microstructure morphology and properties of the composites.（4） A growth process of copper seeds on the graphene sheets using PVP as thecapping agent has been developed to prepare Gs-Cu hybrid nanocomposite.This experiment is a nice improvement over in situ reduction method inpreparing Gs/Cu, which is usually used in situ reduce noble metal nanoparticles, dueto the chemical property of transition metals copper nanoparticles is instable, wouldbe easily oxidized in the preparation process. So we combined with the growth of thecopper nanoparticles preparation method, introduction PVP as a protectant and controlforming agent, Gs@Cu was prepared by nanometer copper seed growth method, SEMresults show that composite morphology of the composite material is better, XRDanalysis shows that there was no copper oxide composite in Gs@Cu, the compositesis a novel non-enzymatic biosensor for glucose, can be successfully applied for thedetermination of glucose.（5） Gs@Cu@Ni temary nanocomposites were prepared via reverse micelletemplate-in situ reduction technologyThe method of reverse micelle template was firstly used in preparingGs@Cu@Ni temary nanocomposites. By this method, the graphene@Cu surfacestructure does not destroy, forming a reverse micelle microreactor in the surface of graphene@Cu, metal precursor of Ni nanoparticles-metal salt solution （NiCl₂）,directly get into the micro reactors and form metal nanoparticles, then Gs@Cu@Ninanocomposites were prepared. The FTIR, elemental analysis, XRD analysis indicatesthat the composite material was prepared. SEM and TEM results show that the alloynanoparticles on graphene surface are clusters of growth, which demonstrate theexistence of micro reactor. Thermogravimetric analysis, electrochemical analysisresults show that the thermal stability of the material is good, high performance assupercapacitor, and compared with the Gs@Cu, this composites are more sensitive toglucose recognition, has the potential application for super capacitor and glucosesensor.