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

The origin of the hollow icosahedral M-12 kernel in metal nanoclusters is under debate. Here the authors demonstrate the Au alloying-induced kernel collapse from small-sized nano-building blocks as a viable approach for the generation of hollow icosahedral M-12 kernel 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 Ag28Cu12(SR)(24) to the template-maintained AuxAg28-xCu12(SR)(24) and then to the template-transformed Au12CuyAg32-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).

Automated summary

This study demonstrates the generation of hollow icosahedral M-12 kernel in metal nanoclusters through Au alloying-induced kernel collapse from small-sized nano-building blocks. The process of kernel evolution and collapse from small nano-building blocks to large nanostructures is outlined, revealing a potential common approach in constructing metallic kernels of nanoclusters and nanoparticles.