State Key Laboratory of Silicon Materials and Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China.
Phys Chem Chem Phys. 2011 Sep 28;13(36):16182-9. doi: 10.1039/c1cp21242g. Epub 2011 Aug 15.
We report the results of density functional theory calculations on cluster-assembled materials based on M(12)N(12) (M = Al, Ga) fullerene-like clusters. Our results show that the M(12)N(12) fullerene-like structure with six isolated four-membered rings (4NRs) and eight six-membered rings (6NRs) has a T(h) symmetry and a large HOMO-LUMO gap, indicating that the M(12)N(12) cluster would be ideal building blocks for the synthesis of cluster-assembled materials. Via the coalescence of M(12)N(12) building blocks, we find that the M(12)N(12) clusters can bind into stable assemblies by either 6NR or 4NR face coalescence, which enables the construction of rhombohedral or cubic nanoporous framework of varying porosity. The rhombohedral-MN phase is energetically more favorable than the cubic-MN phase. The M(12)N(12) fullerene-like structures in both phases are maintained and the M-N bond lengths between M(12)N(12) monomers are slightly larger than that in isolated M(12)N(12) clusters and the bulk wurtzite phases. The band analysis of both phases reveals that they are all wide-gap semiconductors. Because of the nanoporous character of these phases, they could be used for gas storage, heterogeneous catalysis, filtration and so on.
我们报告了基于 M(12)N(12)(M = Al, Ga)富勒烯样团簇的团簇组装材料的密度泛函理论计算结果。我们的结果表明，具有六个孤立的四元环(4NRs)和八个六元环(6NRs)的 M(12)N(12)富勒烯样结构具有 T(h)对称性和较大的 HOMO-LUMO 能隙，表明 M(12)N(12)团簇将是合成团簇组装材料的理想构建块。通过 M(12)N(12)构建块的融合，我们发现 M(12)N(12)团簇可以通过 6NR 或 4NR 面融合形成稳定的组装体，从而构建具有不同孔隙率的菱面体或立方纳米多孔骨架。菱面体-MN 相在能量上比立方-MN 相更有利。两种相中都保持了 M(12)N(12)富勒烯样结构，并且 M(12)N(12)单体之间的 M-N 键长略大于孤立的 M(12)N(12)团簇和体相纤锌矿相中的 M-N 键长。两种相的能带分析表明它们都是宽能隙半导体。由于这些相具有纳米多孔的特性，它们可用于气体储存、多相催化、过滤等。
