Atomic and electronic structure of MoS2 nanoparticles -: art. no. 085410
Atomic and electronic structure of MoS2 nanoparticles -: art. no. 085410
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DOI：
10.1103/physrevb.67.085410
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发表时间：
2003-02-15
影响因子：
3.7
通讯作者：
Norskov, JK
中科院分区：
文献类型：
--
作者：
Bollinger, MV;Jacobsen, KW;Norskov, JK
使用密度泛函理论（DFT），我们提出了一个详细的理论研究二硫化钼纳米粒子。我们专注于边缘结构，和一些不同的边缘终端进行了调查。这些配置中的一些（但不是全部）具有位于边缘的一维金属态。边缘态的电子结构进行了研究，我们讨论了它们对边缘的化学性质的影响。特别是，我们研究了对氢的反应性，并表明，氢可以形成稳定的化学键与两个低米勒指数的边缘二硫化钼。还提出了一个模型计算吉布斯自由能的DFT能量的边缘。该模型使我们能够确定在不同条件下的热力学平衡的稳定的边缘结构。我们发现，绝缘和金属边缘可能是稳定的，这取决于温度和气相的组成。使用Tersoff-Hamann形式主义，扫描隧道显微镜（STM）图像的边缘进行模拟，直接与最近的STM实验比较。通过这种方式，我们确定实验观察到的边缘结构。
Using density-functional theory (DFT) we present a detailed theoretical study of MoS2 nanoparticles. We focus on the edge structures, and a number of different edge terminations are investigated. Several, but not all, of these configurations have one-dimensional metallic states localized at the edges. The electronic structure of the edge states is studied and we discuss their influence on the chemical properties of the edges. In particular, we study the reactivity towards hydrogen and show that hydrogen may form stable chemical bonds with both the two low-Miller indexed edges of MoS2. A model for calculating Gibbs free energy of the edges in terms of the DFT energies is also presented. This model allows us to determine the stable edge structure in thermodynamic equilibrium under different conditions. We find that both the insulating and metallic edges may be stable depending on the temperature and the composition of the gas phase. Using the Tersoff-Hamann formalism, scanning-tunneling microscopy (STM) images of the edges are simulated for direct comparison with recent STM experiments. In this way we identify the experimentally observed edge structure.