In Situ Characterization Of Metal Nanostructures At Single Particle Level

Metal nanostructures have attracted much attention in physics,biology,chemistry and other fields by localized surface plasmon resonance(LSPR).Gold nanostructures have become hot topics due to their preparation with high yield,high stability,and tunable LSPR wavelength.At present,research on metal nanostructures is mainly based on ensemble samples,such as solutions containing metal nanoparticles and the photovoltaic device made by thin films.However,the properties presented by the ensemble samples cannot fully reflect the plasmonic characteristics of metal nanostructures due to average effects.In this work,I explore plasmonic characteristics of gold nanostructures using single particle technique.The main research contents of this paper as followed:1.Synthesis and in situ characterization of gold-ruthenium oxide core-shell(AuNR@RuO2)nanostructure at single particle level:Firstly,AuNR@RuO2 nanostructure with different LSPR wavelengths was synthesized by the hydrothermal method.The gold cores in our core-shell nanostructures were prepared by the oxidation of original gold nanorods(AuNR),Then by combining optical and morphological characterization,the in situ observation was performed on single AuNR@RuO2 nanostructures to compare their size and scattering spectra before and after annealing.Finally,finite-difference time-domain simulation was used to simulate the change of optical properties of RuO2 shell.Our method is expected to be applicable to the optical characteristics of other oxide shells.2.In situ characterization of gold nanoplates at single particle level during growth and self-assembly:Firstly,large-scaled gold nanoplates were synthesized by the polyol method,and in situ observation on the growth of single nanoplates were performed by bright and dark field microscopy to find its growth pattern.Then,the surface of the cleaned gold nanoplate was modified by different types of thiol molecules for the self-assembly of AuNRs.During the process,in situ observation was performed using dark field microscopy and scanning electron microscopy(SEM).The self-assembly of AuNRs on gold nanoplates form the basis of construction of complex metal nanostructures.