Radiological Control of Gold Octahedral and Prism Nanoparticles
- PDF / 1,311,414 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 70 Downloads / 147 Views
1056-HH02-07
Radiological Control of Gold Octahedral and Prism Nanoparticles Tina M. Nenoff1, Jason C. Jones1, Paula P. Provencio2, and Donald T. Berry3 1 Surface and Interface Science, Sandia National Laboratories, PO Box 5800, MS 1415, Albuquerque, NM, 87185-1415 2 Radiation-Solid Interactions, Sandia National Laboratories, PO Box 5800, MS 1421, Albuquerque, NM, 87185-1421 3 Hot Cells and Gamma Facilities, Sandia National Laboratories, PO Box 5800, MS 1143, Albuquerque, NM, 87185-1143 ABSTRACT We report on the fundamental morphology growth of gold-based nanoparticles by solution radiolysis. The radiolysis experiments utilize γ-irradiation by the 60Co source of 1.345 x 105 Ci at Sandia National Laboratories Gamma Irradiation Facility (GIF). Radiolysis of pure gold-polymer solutions with different dose rates and aging time is studied with a focus on the formation of gold nano-octahedra and nano-prism particles. Nanoparticle characterization techniques included are UV-vis and TEM. The data analysis shows that the dose rate dictates the size of the gold nanoparticles formed, similar to that observed in earlier silver studies. At high dose rates, all reducing species are produced and scavenged within a short time, and then coalesce into separate nanoparticles. At low dose rates, the coalescence process is faster than the production rate of the reducing radicals. The reduction of radicals occurs mainly on clusters already formed. The differences in the resultant nanoparticles’ morphology occur due to a combination of dose rate, post irradiation particle aging, and lack of radical scavengers (e.g. isopropyl alcohol), resulting in either gold nano-spheres, octahedral or prism nanoparticles. The progressive evolution with dose rate of the UV-visible absorption spectra of radiation-induced metal clusters is discussed.
INTRODUCTION A great deal of research has focused on the synthesis of nanostructured materials for applications in chemical and biological sensing, [1] catalysis,[2] and electronics [3]. The majority of effort thus far has focused on isotropic, spherical structures. However, researchers have made promising advances recently in controlling nanoparticle size, shape, and composition, [1-4] which results in the tunability of physical and chemical properties of a nanoparticle. [5] Furthermore, a number of research groups have concentrated on triangular nanoprisms due to their unusual optical properties and the recent development of new methods for preparing bulk quantities of them. [4] Depending upon composition and desired dimensions, certain types of prisms can be prepared either thermally or chemically. [4a,b] Gold nanoprisms have been synthesized exclusively by thermal methods with varying degrees of success regarding purity and size control. Recently, methods have been developed for developing large quantities of single purity gold nanoprisms via gold nanoparticle seeds.[6] Herein, we present a new method of synthesizing gold nanoprisms via gamma (γ)radiation. γ-radiation has proven to be a powerful, yet ver
Data Loading...
