A reasonable approach for the generation of hollow icosahedral kernels in metal nanoclusters

Although the hollow icosahedral M(12) kernel has been extensively observed in metal nanoclusters, its origin remains a mystery. Here we report a reasonable avenue for the generation of the hollow icosahedron: the kernel collapse from several small nano-building blocks to an integrated hollow icosahedron. On the basis of the Au alloying processes from Ag(28)Cu(12)(SR)(24) to the template-maintained Au(x)Ag(28-x)Cu(12)(SR)(24) and then to the template-transformed Au(12)Cu(y)Ag(32-y)(SR)(30), the kernel evolution/collapse from “tetrahedral Ag(4) + 4(∗)Ag(3)” to “tetrahedral Au(4) + 4(∗)M(3) (M = Au/Ag)” and then to “hollow icosahedral Au(12)” is mapped out. Significantly, the “kernel collapse” from small-sized nano-building blocks to large-sized nanostructures not only unveils the formation of hollow icosahedral M(12) in this work, but also might be a very common approach in constructing metallic kernels of nanoclusters and nanoparticles (not limited to the M(12) structure).