Since its discovery, the direct imaging and determination of the crystal structure of few-layer graphdiyne has proven difficult because it is too delicate under irradiation by an electron beam. In this work, the crystal structure of a six-layered graphdiyne nanosheet was directly observed by low-voltage transmission electron microscopy (TEM) using low current density. The combined use of high-resolution TEM (HRTEM) simulation, electron energy-loss spectroscopy, and electron diffraction revealed that the as-synthesized nanosheet was crystalline graphdiyne with a thickness of 2.19 nm (corresponding to a thickness of six layers) and showed ABC stacking. Thus, this work provides direct evidence for the existence and crystal structure of few-layer graphdiyne, which is a new type of two-dimensional carbon material complementary to graphene.

中文翻译：

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六层石墨二炔的直接成像和晶体结构测定

自发现以来，事实证明直接成像和确定几层石墨二炔的晶体结构是困难的，因为在电子束的照射下它太微妙了。在这项工作中，使用低电流密度的低压透射电子显微镜（TEM）直接观察了六层石墨二炔纳米片的晶体结构。结合使用高分辨率TEM（HRTEM）模拟，电子能量损失谱和电子衍射，发现合成后的纳米片是晶体石墨二炔，厚度为2.19 nm（相当于六层厚度），并显示出ABC。堆叠。因此，这项工作为少层石墨二炔的存在和晶体结构提供了直接证据，该层是一种与石墨烯互补的新型二维碳材料。