On the role of surface diffusion in determining the shape or morphology of noble-metal nanocrystals

• Type of Material: Article
• Authors: Xiaohu Xia, Emory University; Shuifen Xie, Georgia Institute of Technology; Maochang Liu, Georgia Institute of Technology; Hsin-Chieh Peng, Georgia Institute of Technology; Ning Lu, University of Texas at Dallas; Jinguo Wang, University of Texas at Dallas; Moon J. Kim, University of Texas at Dallas; Younan Xia, Emory University
• Language: English
• Date: 2013-04-23
• Publisher: National Academy of Sciences
• Publication Version: Final Published Version
• Copyright Statement: Copyright © 2020 National Academy of Sciences.
• Final Published Version (URL): http://dx.doi.org/10.1073/pnas.1222109110
• Title of Journal or Parent Work: Proceedings of the National Academy of Sciences
• ISSN: 0027-8424
• Volume: 110
• Issue: 17
• Start Page: 6669
• End Page: 6673
• Grant/Funding Information: As jointly supervised PhD students from Xiamen University and Xi'an Jiaotong University, respectively, S.X. and M.L. were partially supported by Fellowships from the China Scholarship Council.; M.J.K. was supported by the WCU Program from MEST through NRF Grant R31-10026.; Y.X. was also supported by the World Class University (WCU) Program from Ministry of Education, Science and Technology (MEST) through National Research Foundation (NRF) Grant R32-20031.; This work was supported in part by National Science Foundation Grant DMR-1215034; and start-up funds from Georgia Institute of Technology.
• Keywords: Palladium; Surface Properties; Adsorption; Photoelectron Spectroscopy; Metal Nanoparticles; Models, Molecular; Diffusion; Microscopy, Electron, Transmission
• Research Categories: Chemistry, General; Engineering, Biomedical

Abstract

Controlling the shapeormorphologyofmetalnanocrystalsiscentral to the realization of their many applications in catalysis, plasmonics, and electronics. In one of the approaches, the metal nanocrystals are grown from seeds of certain crystallinity through the addition of atomic species. In this case, manipulating the rates at which the atomic species are added onto different crystallographic planes of a seed has been actively explored to control the growth pattern of a seed and thereby the shape or morphology taken by the final product. Upon deposition, however, the adsorbed atoms (adatoms) may not stay atthe same sites where the depositions occur. Instead, they can migrate to other sites on the seed owing to the involvement of surface diffusion, and this could lead to unexpected deviations from a desired growth pathway. Herein, we demonstrated that the growth pathway of a seed is indeed determined by the ratio between the rates for atom deposition and surface diffusion. Our result suggests that surface diffusion needs to be taken into account when controlling the shape or morphology of metal nanocrystals.