Parilla Philip A, Dillon Anne C, Parkinson Bruce A, Jones Kim M, Alleman Jeff, Riker Gerald, Ginley David S, Heben Michael J
National Renewable Energy Laboratory, Golden, Colorado 80401, and Chemistry Department, Colorado State University, Fort Collins, Colorado 80523.
J Phys Chem B. 2004 May 20;108(20):6197-207. doi: 10.1021/jp036202+.
Pulsed laser vaporization has been used to produce nanooctahedra of MoS2 and MoSe2. The nanooctahedra primarily form in two- or three-layer nested octahedra, although nesting up to five layers has been observed. Tilting the TEM sample stage and mapping how the images of single particles transformed provided the evidence to verify their octahedral geometry. Analysis of 30 two- and three-layered octahedra showed that their outer edge lengths clustered at approximately 3.8 nm and approximately 5.1 nm, respectively. This discreet sizing and the high symmetry of these closed nanooctahedra represent the closest inorganic analogy yet to the carbon fullerenes. The geometrical implications for forming octahedra from these layered compounds are investigated by considering different atomic arrangements assuming either trigonal prismatic or octahedral coordination around the Mo atom and yields two possible configurations for the actual structure of the nanooctahedra. A preliminary survey of pulsed laser vaporization of other layered metal chalcogenides shows that these dichalcogenides differ in their tendency to form small closed layered fullerene-like structures. These materials can be ranked from highest tendency to lowest as follows: NbSe2, WS2, WSe2, SnS2, TaS2, GaS, ReS2, and MoTe2.
脉冲激光蒸发已被用于制备二硫化钼（MoS₂）和二硒化钼（MoSe₂）的纳米八面体。纳米八面体主要以两层或三层嵌套八面体的形式形成，不过也观察到了多达五层的嵌套。倾斜透射电子显微镜（TEM）样品台并绘制单个粒子图像如何变化，为验证它们的八面体几何形状提供了证据。对30个两层和三层八面体的分析表明，它们的外边长分别聚集在约3.8纳米和约5.1纳米处。这种离散的尺寸以及这些封闭纳米八面体的高度对称性代表了迄今为止与碳富勒烯最接近的无机类似物。通过考虑围绕钼原子的三角棱柱或八面体配位的不同原子排列，研究了由这些层状化合物形成八面体的几何意义，并得出了纳米八面体实际结构的两种可能构型。对其他层状金属硫族化合物的脉冲激光蒸发的初步调查表明，这些二硫族化合物形成小的封闭层状富勒烯样结构的倾向有所不同。这些材料按形成倾向从高到低排序如下：二硒化铌（NbSe₂）、二硫化钨（WS₂）、二硒化钨（WSe₂）、二硫化锡（SnS₂）、二硫化钽（TaS₂）、硫化镓（GaS）、二硫化铼（ReS₂）和碲化钼（MoTe₂）。
