Medium-sized Au40(SR)24 and Au52(SR)32 nanoclusters with distinct gold-kernel structures and spectroscopic features.
Medium-sized Au40(SR)24 and Au52(SR)32 nanoclusters with distinct gold-kernel structures and spectroscopic features.
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DOI：
10.1039/c5nr07810e
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发表时间：
2016-01
期刊：
影响因子：
6.7
通讯作者：
W. Xu;Yadong Li;Yi Gao;X. Zeng
中科院分区：
文献类型：
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作者：
W. Xu;Yadong Li;Yi Gao;X. Zeng
我们已经分析了两种中等大小的硫醇盐保护的金纳米颗粒（RS-AuNP）Au 40（SR）24和Au52（SR）32的结构，并鉴定了它们的Au内核中的不同结构特征[Sci.高级，2015，1，e1500425]。我们发现Au 40（SR）24和Au 52（SR）32纳米团簇的Au内核都可以归类为互穿的立方八面体。收集具有立方八面体核的RS-AuNP的模拟X射线衍射图案，然后将其与从先前实验中鉴定的另外两种主要Au核（即Ino-十面体核和二十面体核）的RS-AuNP的X射线衍射图案进行比较。具有三种不同类型的Au核的RS-AuNPs的不同X射线衍射图案可以用作RS-AuNPs结构的未来研究的签名特征。利用含时密度泛函理论计算了Au_（40）（SR）_（24）和Au_（52）（SR）_（32）的UV/维斯吸收光谱和Kohn-Sham轨道能级图。Au_（40）（SR）_（24）和Au_（52）（SR）_（32）的外推光学带边分别为1.1eV和1.25eV。两个团簇的紫外/维斯吸收光谱中的特征峰均属于d → sp电子跃迁。最后，以CO氧化为探针考察了Au_（40）（SR）_（24）和Au_（52）（SR）_（32）的催化活性。这两种中等大小的硫醇盐保护的金簇可以作为有效的独立的纳米催化剂。
We have analyzed the structures of two medium-sized thiolate-protected gold nanoparticles (RS-AuNPs) Au40(SR)24 and Au52(SR)32 and identified the distinct structural features in their Au kernels [Sci. Adv., 2015, 1, e1500425]. We find that both Au kernels of the Au40(SR)24 and Au52(SR)32 nanoclusters can be classified as interpenetrating cuboctahedra. Simulated X-ray diffraction patterns of the RS-AuNPs with the cuboctahedral kernel are collected and then compared with the X-ray diffraction patterns of the RS-AuNPs of two other prevailing Au-kernels identified from previous experiments, namely the Ino-decahedral kernel and icosahedral kernel. The distinct X-ray diffraction patterns of RS-AuNPs with the three different types of Au-kernels can be utilized as signature features for future studies of structures of RS-AuNPs. Moreover, the simulated UV/Vis absorption spectra and Kohn-Sham orbital energy-level diagrams are obtained for the Au40(SR)24 and Au52(SR)32, on the basis of time-dependent density functional theory computation. The extrapolated optical band-edges of Au40(SR)24 and Au52(SR)32 are 1.1 eV and 1.25 eV, respectively. The feature peaks in the UV/Vis absorption spectra of the two clusters can be attributed to the d → sp electronic transition. Lastly, the catalytic activities of the Au40(SR)24 and Au52(SR)32 are examined using CO oxidation as a probe. Both medium-sized thiolate-protected gold clusters can serve as effective stand-alone nanocatalysts.