Transforming C60 molecules into graphene quantum dots
Transforming C60 molecules into graphene quantum dots
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DOI：
10.1038/nnano.2011.30
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发表时间：
2011-04-01
影响因子：
38.3
通讯作者：
Loh, Kian Ping
中科院分区：
文献类型：
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作者：
Lu, Jiong;Yeo, Pei Shan Emmeline;Loh, Kian Ping
利用离子、表面碰撞或热效应使富勒烯碎裂是一个复杂的过程，通常会形成大小不一的小碳团簇。在这里，我们展示了几何上定义良好的石墨烯量子点可以用C-60分子作为前体在钌表面上合成。扫描隧道显微镜成像和密度泛函理论计算表明，这些结构是通过钌催化的C-60打开笼形成的。在此过程中，强烈的C-60-Ru相互作用诱导Ru单晶中形成表面空位，随后C-60分子在表面嵌入。嵌入的分子在高温下破碎，然后产生碳团簇，这些碳团簇经过扩散和聚集形成石墨烯量子点。石墨烯的平衡形状可以通过优化退火温度和碳团簇的密度来定制。
The fragmentation of fullerenes using ions, surface collisions or thermal effects is a complex process that typically leads to the formation of small carbon clusters of variable size. Here, we show that geometrically well-defined graphene quantum dots can be synthesized on a ruthenium surface using C-60 molecules as a precursor. Scanning tunnelling microscopy imaging, supported by density functional theory calculations, suggests that the structures are formed through the ruthenium-catalysed cage-opening of C-60. In this process, the strong C-60-Ru interaction induces the formation of surface vacancies in the Ru single crystal and a subsequent embedding of C-60 molecules in the surface. The fragmentation of the embedded molecules at elevated temperatures then produces carbon clusters that undergo diffusion and aggregation to form graphene quantum dots. The equilibrium shape of the graphene can be tailored by optimizing the annealing temperature and the density of the carbon clusters.