Tailoring Electronic Structure Through Alloying: The AgnCu34-n (n=0-34) Nanoparticle Family

    Authors

    H. Yildirim; A. Kara;T. S. Rahman

    Comments

    Authors: contact us about adding a copy of your work at STARS@ucf.edu

    Abbreviated Journal Title

    J. Phys. Chem. C

    Keywords

    TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; BIMETALLIC NANOPARTICLES; GENETIC ALGORITHM; TRANSITION-METALS; CLUSTERS; SIZE; NANOALLOYS; STABILITY; GOLD; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, ; Multidisciplinary

    Abstract

    Electronic structures of the free-standing core shell (Cu@Ag) AgnCu34-n (n = 0-34) nanoalloy family are studied as a function of stoichiometry using ab initio total energy electronic structure calculations. Our calculations show that progressive alloying significantly alters the coordination distribution, bond lengths, formation energies, and the electronic densities of states. Changes in coordination and elemental environment are reflected in the electronic densities of states, which broaden or narrow as a result of hybridization between the Cu and the Ag atoms. The densities of states of Ag atoms in Ag-rich nanoparticles show large broadening when a single Cu atom is introduced, followed by substantial deviation of the position of the center of d states from that of the pristine (Ag-34) nanoparticle. Such deviation is found to persist for nonsymmetric nanoparticles. The calculated HOMO-LUMO gaps vary between 0.2 and 0.9 eV within the family. The magnitude of the gaps is found to be strongly dependent on the geometric structure determined by the species ratio: the particles belonging to two ends of the NP family have relatively small gaps, and no overriding symmetry, whereas those toward the middle of the family exhibit high symmetry and larger gaps. The calculated ionization energies show no monotonic dependence on the Cu-to-Ag ratio and fluctuate within 500 meV as the stoichiometry changes.

    Journal Title

    Journal of Physical Chemistry C

    Volume

    116

    Issue/Number

    1

    Publication Date

    1-1-2012

    Document Type

    Article

    Language

    English

    First Page

    281

    Last Page

    291

    WOS Identifier

    WOS:000298978700035

    ISSN

    1932-7447

    Share

    COinS