On the Crystallography of Silver Nanoparticles with Different Shapes

Abstract

The crystallographic properties of silver nanoparticles with different morphologies (two different kinds of spheres, cubes, platelets, and rods) were derived from X-ray powder diffraction and electron microscopy. The size of the metallic particle core was determined by scanning electron microscopy, and the colloidal stability and the hydrodynamic particle diameter were analyzed by dynamic light scattering. The preferred crystallographic orientation (texture) as obtained by X-ray powder diffraction, including pole figure analysis, and high resolution transmission electron microscopy showed the crystallographic nature of the spheres (almost no texture), the cubes (terminated by {100} faces), the platelets (terminated by {111} faces), and the rods (grown from pentagonal twins along [110] and terminated by {100} faces). The crystallite size was determined by Rietveld refinement of X-ray powder diffraction data and agreed well with the transmission electron microscopic data.

Deciphering the Surface Composition and the Internal Structure of Alloyed Silver–Gold Nanoparticles

“…Clearly, the particle shape is not fully spherical as facetted and elongated particles were observed, which was more pronounced in monometallic particles and less observed in alloy particles. HRTEM images show the presence of several domain and grain boundaries in polycrystalline nanoparticles, in good agreement with earlier studies on silver nanoparticles . These results confirm the crystallite size calculations after Rietveld refinement that showed a smaller crystallite size (around 12 nm) than the nanoparticle diameter (around 35 nm), confirming the polycrystallinity.…”

“…HRTEM images showt he presenceo fs everal domain and grain boundaries in polycrystalline nanoparticles, in good agreement with earlier studies on silver nanoparticles. [29] These results confirm the crystallite size calculations after Rietveld refinement that showedasmaller crystallite size (around 12 nm) than the nanoparticle diameter (around 35 nm), confirming the poly- crystallinity.High-angle annular dark field (HAADF) images with corresponding individual particle EDX maps and HRTEM images of bimetallic nanoparticles are shown in Figures 8,9,and 10. In some cases,t he EDX maps showedi rregularly distributed silver-rich patches at the surface of the particles.…”

Anin situSAXS investigation of the formation of silver nanoparticles and bimetallic silver–gold nanoparticles in controlled wet-chemical reduction synthesis

“…This polycrystallinity with a vefold symmetry and a ratio of crystallite size : particle diameter of 1 : 3 is in excellent agreement with earlier studies. 8,51,52 A detailed analysis of the HRTEM micrograph and the corresponding FFT analysis show the presence of (111) crystallographic planes inside one domain with an interplanar distance (d hkl ) of 2.34Å (ICDD card 04-0783). 6,53 The smaller nanoparticles with a diameter of 2-3 nm are also crystalline with the same interplanar distance (2.34Å), which corresponds to the (111) plane.…”

Molecular Dynamics Simulations of Silver Nanoparticles of Cubic and Bipyramidal Shape

“…In recent years, particular attention has been paid to synthesis and characterization of sharp-edged AgNPs [4], because their optical, electronic and catalytic properties are strongly dependent on the number of constituent atoms and morphology [1,[5][6][7]. The simple chemistry enables the tuning of these properties by varying the shape, ratio and number of the corners and edges that holds promise for their applications in many industrially and technologically important phenomena, ranging from chemical engineering to nano-science [8][9][10][11].…”