Preparation And Properties Of Copper And Nickel Nanoparticles/CVD Graphene Hybrid

Metal nanoparticles have a wide range of applications in sensing,catalysis and other fields because of their high surface area and surface activity.Copper,nickel nanoparticles,rich in content and low in price,are expected to replace traditional precious metals,such as gold and silver,in the field of catalysis and sensing.Graphene has become an ideal carrier material for loading metal nanoparticles due to its excellent electrical,mechanical and thermal properties,good chemical stability as well as large specific surface area.Moreover,the high conductivity of graphene provides a channel for charge transfer,thus it is expected to further enhance the catalytic and sensing properties of single metal nanoparticles and graphene through the synergistic effect of metal nanoparticles and graphene.In this paper,copper and nickel nanoparticles/chemical vapor deposition(CVD)graphene hybrid structures were prepared by galvanic displacement reaction,galvanostatic deposition and CVD method.Optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM),X ray diffraction(XRD)and Raman spectroscopy were used to characterize the prepared materials.The composite was applied to the catalysis of p-nitrophenol and the sensing of hydrogen peroxide.The main results are as follows:(1)Preparation of high quality two-dimensional graphene film by CVD method,including pretreatment of substrate,preparation and transfer of graphene.Preparation and transfer of three-dimensional(3D)graphene were also studied.Three dimensional graphene with complete 3D pore structure and excellent mechanical properties was prepared,which act as the carrier materials for subsequent nanoparticles loading.(2)The square copper nanoparticles/3D graphene composite with uniform size was prepared by displacement reaction.The composite was applied to the sensing of hydrogen peroxide and the catalysis of p-nitrophenol,showing excellent catalytic and sensing properties.For hydrogen peroxide sensing,it shows high sensitivity(0.11396 ? A(mA)-1 cm-2),wide linear range(50 ?M-9.65 mM),low response time(3s)and low detection limit(1 ?M).When the composite was used as catalyst,the catalytic constant of the composite with volume of 1×1×0.15cm3 is 0.05615s-1.(3)Using arginine,we prepared spherical copper nanoparticles/3D graphene composite.The prepared composite has excellent catalytic activity(k= 0.71612min-1)and reproducibility for catalytic reaction of p-nitrophenol.(4)Nickel nanoparticles/3D graphene composite was successfully prepared by electrodeposition.The nickel nanoparticles/3D graphene composite with the best size and distribution was prepared by using 0.1M nickel sulfate/0.1M sulfuric acid mixed solution as deposition solution,deposition time of 30s and deposition current of 0.25A.The composite shows good catalytic efficiency(catalytic constant k=0.56787min-1),good durability and reproducibility for the catalytic reaction of p-nitrophenol.(5)Three kinds of hybrid structures of graphene coated copper nanoparticles,nickel nanoparticles and copper nickel alloy nanoparticles were prepared by CVD method.Graphene coated copper nanoparticles hybrid structure shows the best catalytic efficiency(k=2.05971min-1)for catalytic reduction of p-nitrophenol,which is related to the catalytic activity of copper nanoparticles,the size and distribution of copper nanoparticles,and the transport properties of graphene.