Barnard Amanda S, Curtiss Larry A
Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK.
Chemphyschem. 2006 Jul 17;7(7):1544-53. doi: 10.1002/cphc.200600107.
Although a number of computational studies have examined the relative stability of icosahedral and decahedral gold clusters from 1 to 3 nm in size, few studies have focussed on the variety of face-centered cubic (fcc) nanoparticles in this size regime. In most cases small fcc gold particles are assumed to adopt the truncated octahedral shape, but in light of the fact that the shape and structure of gold nanoparticles is known to vary, the relative stability of fcc polyhedra may change with size. Presented here are results of first-principles calculations investigating the preferred shape of gold particles less than 3 nm in size. Our results indicate that the equilibrium shape of fcc gold nanoparticles less than 1 nm is the cuboctahedron, but this shape rapidly becomes energetically unstable with respect to the truncated octahedron, octahedron and truncated cube shapes as the size increases.
尽管已有多项计算研究考察了尺寸在1至3纳米之间的二十面体和十面体金团簇的相对稳定性，但很少有研究关注这一尺寸范围内各种面心立方（fcc）纳米颗粒。在大多数情况下，小的面心立方金颗粒被假定为截顶八面体形状，但鉴于已知金纳米颗粒的形状和结构会发生变化，面心立方多面体的相对稳定性可能会随尺寸而改变。本文展示了第一性原理计算的结果，该计算研究了尺寸小于3纳米的金颗粒的优选形状。我们的结果表明，尺寸小于1纳米的面心立方金纳米颗粒的平衡形状是立方八面体，但随着尺寸增加，相对于截顶八面体、八面体和截顶立方体形状，这种形状在能量上会迅速变得不稳定。
