Thermal Decomposition Synthesis And Property Of Silver/Silica Composite

In precious metals,the localized surface plasmon resonance(LSPR)property of silver materials is prominent,which brings a comparatively wide range of applications in optics.However,silver nanoparticles are extremely easy to reunite because of their high chemical activity.The core-shell structure formed by coating a layer of other material on the surface of silver particles not only prevents the agglomeration of silver particles,but also extends applications of silver materials.Also,silica is inert and have strong scattering effect on light.due to these merits of silica,the optical properties of silver/silica composites are concerned greatly by academia.Therefore,it is very important to find a simple,feasible,cheap and efficient method for preparing silver/silica compositesIn this paper,silver/silica composites were prepared by thermal decomposition using silver nitrate and silica sol as silver and silicon source,respectively.The synthesis conditions of silver/silica nanoparticles can be dominated by altering the holding time and concentration of silver nitrate and temperature.Finally,we summarized the optimized experimental conditions for the preparation of composite particles.As a result,the highly monodisperse,uniform nanoparticles with a spherical silver core in an average size of 5 nm and a silica shell about 17 nm in diameter were prepared.As-prepared nanoparticles were characterized by UV-Vis spectrometer,we found that the morphology and size of silver particles changed ?max of LSPR peak of silver/silica composites,in return,these changes influenced applications of materials in optics.When nanoparticles were uniformly dispersed in different solvents,Refractive Index Sensitivity(RIS)effect of those particles was obtained according to the relation between refractive index(n)of solvents and corresponding ?max of LSPR peak.Experimental results indicated that the higher value of RIS,the more sensitive ability of silver/silica composites to surrounding environment,so silver/silica composites are suitable as probes.On the contrary,as markers used in drug tracking,signal detection and so on.