Evolution of stellated gold nanoparticles:New conceptual insights into controlling the surface processes  

作　　者：Gurvinder Singh Hesamodin Jami Pooria Lesani Shubhayan B.hattacharya Yogambha Ramaswamy Prem BBisht Hala Zreiqat 

机构地区：[1]ARC Centre for Innovative BioEngineering,Tissue Engineering and Biomaterials Research Unit,Sydney Nano Institute and the School oj Biomedical Engineering,The University of Sydney,NSW 2008,Australia [2]Department of Physics,Indian Institute of Technology Madras,Chennai,India

出　　处：《Nano Research》2022年第2期1260-1268,共9页纳米研究（英文版）

摘　　要：Understanding the surface processes(deposition and surface diffusion)that occur at or close to the surface of growing nanoparticles is important for fabricating reproducibly stellated or branched gold nanoparticles with precise control over arm length and spatial orientation of arms around the core.By employing a simple seed-mediated strategy,we investigate the key synthetic variables for precise tuning of in situ surface processes(competition between the deposition and surface diffusion).These variables include the reduction rate of a reaction,the packing density of molecules/ions on the high surface energy facets,and temperature.As a result,the thermodynamically stabilized nanoparticles(cuboctahedron and truncated cube)and kinetic products(cube,concave cube,octapod,stellated octahedron,and rhombic dodecahedron)in different sizes with high quantitative shape yield(>80%)can be obtained depending on the reduction rate of reaction and the packing density of molecules/ions.With computer simulation,we studied the stability of stellated(branched structure)and non-stellated(non-branched structure)gold nanoparticles at high temperature.We construct a morphology phase diagram by varying different synthetic parameters,illustrating the formation of both stellated and non-stellated gold nanoparticles in a range of reaction conditions.The stellated gold nanoparticles display shape-dependent optical properties and can be self-assembled into highly ordered superstructures to achieve an enhanced plasmonic response.Our strategy can be applied to other metal systems,allowing for the rational design of advanced new stellated metal nanoparticles with fascinating symmetry dependent plasmonic,catalytic,and electronic properties for technological applications.

关 键 词：surface diffusion shape control stellated nanoparticles SELF-ASSEMBLY nanoplasmonics octapod stellated octahedron 

分 类 号：TB3[一般工业技术—材料科学与工程]