Preparation And Study On Catalytic Performance Of Composites Of Gold Nanoparticles And Carbon Materials

Nanomaterials benefit from their special spatial dimensions and have characteristics different from molecules,atoms,and macroscopic substances.Among them,gold nanomaterials have the characteristics of controllable morphology and particle size,good biocompatibility,high chemical stability,excellent surface modification and good surface plasmon resonance effect.And optics and other fields have good application prospects.Graphene oxide and carbon nanotubes have the characteristics of large surface area,excellent electrical conductivity,good biocompatibility,high chemical stability and strong functional modification,and are suitable for loading gold nanomaterials.The composite material formed after the gold nanomaterial is loaded can improve its catalytic performance due to the synergistic effect between the two.The main research content of this subject includes the following three parts.(1)Using solution synthesis method,using chloroauric acid(HAuCl4)as the precursor,with the help of structure directing agent cetyltrimethylammonium bromide(CTAB),in graphene oxide(GO)suspension,In-situ synthesis of decahedral gold nanoparticles/graphene oxide composite materials.Use transmission electron microscope(TEM),Raman spectroscopy(Raman),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS)to characterize the morphology,structure and surface chemical properties of composite materials.The results show that the experimentally prepared gold nanoparticles are decahedrons,with an average particle size of 30-50 nm,uniformly distributed on the surface of graphene oxide;XRD characterization indicates that the decahedral gold nanoparticles are cubic structure;Raman and XPS characterizations indicate that they are in decahedron During the growth of gold nanoparticles,a large number of oxygen-containing functional groups on the surface of graphene oxide are consumed,and covalent bonds are formed between the two.(2)Using the seed-mediated method,the strong reducing agent sodium borohydride(NaBH4)is used to reduce Au(0)on carbon nanotubes(CNTs),which is the gold seed,and the structure-directing agent CTAB is used in the growth solution.Synthesis of polyhedral gold nanoparticle/carbon nanotube composite material in situ.Use TEM,Raman,XRD,XPS to characterize composite materials.TEM characterization shows that the prepared gold nanoparticles are polyhedral with an average particle size of about 1020 nm;XRD characterization shows that the polyhedral gold nanoparticles have a cubic structure;Raman characterization shows that in the process of forming composite materials,gold ions and carbon nanotubes are Reduction,a covalent bond is formed between the two.XPS characterization shows that the oxygen-containing functional groups on the surface of carbon nanotubes are significantly reduced,and Au(0)is formed on the surface.(3)The catalytic properties of decahedral gold nanoparticles/graphene oxide and polyhedral gold nanoparticles/carbon nanotube composites were studied.An ultravioletvisible(UV-vis)spectrophotometer was used to test the performance of the composite material for catalytic degradation of p-nitrophenol,and the reusability of the composite material was tested.The results show that the reaction rate constant of the decahedral gold nanoparticles/graphene oxide composite is 0.0884 mmol/L·min,which can catalytically degrade all p-nitrophenol(4-NP)within 10 minutes,and the composite material is It can be reused in the secondary catalytic cycle.The reaction rate constant of the polyhedral gold nanoparticle/carbon nanotube composite is 0.0778 mmol/L·min,which can catalyze most of the p-nitrophenol within 10 minutes,and the composite can be reused in five catalytic cycles.Figure[31]Table[8]Reference[102]...