Yu Hongtao, Liu Yi, Brock Stephanie L
Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.
Inorg Chem. 2008 Mar 3;47(5):1428-34. doi: 10.1021/ic701020s. Epub 2008 Feb 8.
MoS2 nanoparticles of size <5 nm have been synthesized via the reaction of Mo(CO)6 with elemental sulfur in trioctylphosphine oxide and 1-octadecene at temperatures from 270 to 330 degrees C. The MoS2 nanoparticles are discrete and dispersible in a variety of nonpolar organic solvents, including toluene, chloroform, and pyridine. The size of the particles can be effectively tuned by varying the temperature, yielding nearly monodisperse samples (<10% standard deviation) as evidenced by transmission electron microscopy (TEM). Additionally, larger (20-50 nm) onion- and tube-shaped MoS2 nanoparticles can be obtained by decreasing the amount of the coordinating solvent (trioctylphosphine oxide) relative to 1-octadecene. As-prepared samples are poorly crystalline, showing only weak contrast in the TEM and an absence of the first-order (00 l) reflection in powder X-ray diffraction that is indicative of regular MoS2 stacking. Samples heated in situ in the TEM are observed to develop contrast and lattice fringes as the temperature is raised to 550 degrees C. Ex-situ heated samples show the appearance of the first order (00l) reflection at temperatures >870 degrees C.
通过在270至330摄氏度的温度下，使六羰基钼与元素硫在三辛基氧化膦和1 - 十八烯中反应，合成了尺寸小于5纳米的二硫化钼纳米颗粒。这些二硫化钼纳米颗粒是离散的，可分散在多种非极性有机溶剂中，包括甲苯、氯仿和吡啶。通过改变温度可以有效地调节颗粒的尺寸，如透射电子显微镜（TEM）所示，可得到近乎单分散的样品（标准偏差<10%）。此外，相对于1 - 十八烯，通过减少配位溶剂（三辛基氧化膦）的量，可以获得更大尺寸（20 - 50纳米）的洋葱状和管状二硫化钼纳米颗粒。所制备的样品结晶性较差，在TEM中仅显示出微弱的对比度，并且在粉末X射线衍射中没有表示二硫化钼规则堆叠的一级（00l）反射。在TEM中原位加热样品时，当温度升高到550摄氏度时，观察到对比度和晶格条纹出现。非原位加热的样品在温度>870摄氏度时显示出一级（00l）反射的出现。
