Structural influence of transition metal (Sc, Y, and Lu) atoms inside gold nanoparticles

摘要

We theoretically investigated the influences of dopant transition metal atoms on structures and stability of gold nanoparticles. The optimized structures of Au3M and Au3M in an Au-32 cage (M=Au, Sc, Y, and Lu) obtained using relativistic density functional theory, show different configurations. Substitutions of one Au atom in the Au-4 cluster by only one M atom cause the Au3M clusters to form equilateral triangles where M atoms prefer the central position, which is different from the original rhombus structure of a pure Au-4 cluster. All Au3M nanoparticles, however, assume stable tetrahedral configurations in the Au-32 cage. Analysis of electronic structures indicates that the equilateral triangle Au3M nanoparticles have higher chemical stability, in other words, lower reactivity than Au3M@Au-32, while interaction energies between M and Au atoms in the Au3M are smaller than those in Au3M@Au-32. Different amounts of charge transfer and orbital hybridizations between the Au and M cause the change of the chemical stability and interaction energies. Our results indicate the potential manipulation of gold nanoparticle reactivity by metal substitution.