Title | In situ and ex situ studies of platinum nanocrystals: Growth and evolution in solution |
Publication Type | Journal Article |
Year of Publication | 2009 |
Authors | Cheong, S., Watt J., Ingham B., Toney M.F., and Tilley R.D. |
Journal | Journal of the American Chemical Society |
Volume | 131 |
Issue | 40 |
Pagination | 14590 - 14595 |
Date Published | 2009 |
ISSN | 00027863 (ISSN) |
Keywords | article, Branched structures, concentration (parameters), controlled study, Etching process, Ex situ, Faceted morphology, Growth mechanisms, growth rate, Growth stages, High resolution transmission electron microscopy, In-situ, In-Situ Study, molecular evolution, morphology, Morphology transformations, nanocrystal, Nanocrystals, nanomaterial, Platinum, Platinum nanocrystals, Precursor concentration, Reaction rates, Selective growth, solution and solubility, synchrotron, TEM, Thermodynamics, Transmission electron microscopy, X ray diffraction, X ray diffraction analysis, XRD |
Abstract | In situ studies on the growth and evolution of platinum nanocrystals in solution were carried out using synchrotron-based X-ray diffraction (XRD) techniques. Ex situ low- and high-resolution transmission electron microscopy (TEM) were used to investigate the nanocrystal morphologies through the different growth stages. In a reaction with low precursor concentration, both XRD and TEM results show that growth occurs at a relatively slow rate and yields faceted morphologies, which are characteristic of a thermodynamically controlled regime. In contrast, the platinum nanocrystals in the high-concentration reaction form branched structures and grow at much greater rates under a kinetically controlled regime. Additionally the growth mechanism of the high-concentration reaction involves a morphology transformation from octapod-like shapes to porous nanostructures, which is brought about by a novel mechanism involving selective growth and etching processes that occur simultaneously and at comparable rates. © 2009 American Chemical Society. |
URL | http://www.scopus.com/inward/record.url?eid=2-s2.0-70349903135&partnerID=40&md5=ef6c5f9d1ecd09e1399b1d9630b29f85 |
DOI | 10.1021/ja9065688 |