The Study Of Synthesis And Properties Of Monodisperse Noble Metal(Au,AuAg Alloy) Nanoparticles

Noble metal Au nanoparticles(AuNPs)and AuAg alloy nanoparticles(NPs)as a kind of new materials,are widely used in catalysis,biological labeling,medical diagnosis,industry of fine chemicals and fuel cell etc.because of their special properties of Surface Plasmon Resonance(SPR)and excellent biocompatibility as well as high catalytic activity and good stability.It is significantly important to study the influencing factors and growth mechanism in synthetic process of AuNPs and alloy NPs to obtain the controllable preparation of monodisperse noble metal nanoparticles,and to explore the properties and applications of special materials.In this thesis,AuNPs and AuAg alloy NPs were synthesized by the sacrificial template method and seed-mediated growth method,respectively.Furthermore,we also studied the effect of the solvent effects on the monodisperse of final Au NPs in the reaction process.The morphology,composition and crystal structure of the NPs were characterized and analyzed by X-ray Diffractomer(XRD),Ultraviolet-Visibale Spectrophotometer(UV-vis),Transmission Electron Microscopy(TEM)and other analysis technology.Moreover,we explored the catalytic and SPR properties of NPs.This thesis consists of three parts:(1)The synthesis of highly monodisperse Au nanoparticles with Co nanoparticles as sacrificial template.The Au nanoparticles were characterized by UV-vis,TEM and XRD.The results show that the average particle size of nanoparticles is about 5.5nm,and it can easily adjust the morphology of the final product by controlling the molar ratio between cobalt NPs and tetrachloroaurate(III)trihydrate(HAuCl4·4H2O).(2)In order to explore the law of solvent influence of spatial configuration and different polarity on the synthesis of AuNPs,a series of experiments using oleylamine as the reducing agent was studied.The research was based on the optical absorption peaks of the particle size and the TEM image of the morphology of the obtained product.(3)A series of AuAg alloy nanoparticles with good morphology were synthesized by controlling the molar ratio of the silver seeds and HAuCl4·4H2O by seed-mediated growth method.The relationship between the composition of alloy particles and the corresponding SPR were studied by the research of alloy NPs UV-vis absorption peak.Meanwhile,the catalytic reduction of 4-nitrophenol(4-NPh)and sodium borohydride(NaBH4)were studied in the presence of alloy NPs.