Layered transition metal dichalcogenide (TMD) crystals in reduced dimensions have exhibited a wide range of extraordinary physical and chemical properties spanning from exotic quantum phenomena to unusually superior chemical reactivity. Their anisotropic van der Waals (vdW) bonding nature enables them to commonly possess two-dimensional (2D) structures which have been rigorously investigated recently. Nonetheless, TMD crystals in quasi zero-dimensional (0D) forms, i.e., TMD fullerenes, have not been explored in depth from the perspective of reproducible synthesis and process–structure correlation. Herein, we report a controlled synthesis of inorganic fullerene platinum diselenide (PtSe₂) via a thermal selenization of Pt nanostructured precursors. We identified a conversion of Pt nanocubes to PtSe₂ “onion-like” fullerenes, dictated by a well-defined isotropic volume expansion. Extensive transmission electron microscopy (TEM) inspections revealed that there exists a certain size-dependency which leads to the preferable growth of PtSe₂ fullerenes over 2D PtSe₂ platelets. The underlying principle for this size-dependent growth is discussed in the context of surface energy minimization. Furthermore, the PtSe₂ fullerenes were verified to possess a large degree of unsaturated dangling bonds as well as internal strain, verified by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) as well as a geometric phase analysis (GPA). This study sheds light on synthesizing a wide range of TMD-based fullerenes which will foster the discovery of novel physical and chemical properties in quasi 0D material systems.

中文翻译：

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二硒化铂（PtSe2）无机富勒烯的可控合成

尺寸减小的层状过渡金属二硫化二氢（TMD）晶体具有广泛的非凡物理和化学性质，从奇特的量子现象到异常优异的化学反应性。它们的各向异性范德华（vdW）键合性质使它们通常拥有二维（2D）结构，最近已对其进行了严格的研究。但是，尚未从可复制的合成和过程-结构相关性的角度深入研究准零维（0D）形式的TMD晶体，即TMD富勒烯。在这里，我们报告了可控合成的无机富勒烯二硒化铂（PtSe ₂）通过铂纳米结构前体的热硒化。我们确定了Pt纳米立方体到PtSe ₂ “洋葱状”富勒烯的转化，这由明确定义的各向同性体积膨胀决定。广泛的透射电子显微镜（TEM）检查显示，存在一定的尺寸依赖性，这导致PtSe ₂富勒烯比2D PtSe ₂血小板具有更好的生长。在表面能最小化的背景下讨论了这种与尺寸有关的增长的基本原理。此外，PtSe ₂富勒烯经证实具有很大程度的不饱和悬空键和内部应变，并通过拉曼光谱和X射线光电子能谱（XPS）以及几何相分析（GPA）进行了验证。这项研究为合成大量基于TMD的富勒烯提供了启示，这将促进在准0D材料系统中发现新的物理和化学性质。