A variety of two-dimensional materials have been reported in recent years, yet single-element systems such as graphene and black phosphorus have remained rare. Boron analogues have been predicted, as boron atoms possess a short covalent radius and the flexibility to adopt sp2 hybridization, features that favour the formation of two-dimensional allotropes, and one example of such a borophene material has been reported recently. Here, we present a parallel experimental work showing that two-dimensional boron sheets can be grown epitaxially on a Ag(111) substrate. Two types of boron sheet, a β12 sheet and a χ3 sheet, both exhibiting a triangular lattice but with different arrangements of periodic holes, are observed by scanning tunnelling microscopy. Density functional theory simulations agree well with experiments, and indicate that both sheets are planar without obvious vertical undulations. The boron sheets are quite inert to oxidization and interact only weakly with their substrate. We envisage that such boron sheets may find applications in electronic devices in the future.
Nature Chemistry (2016) doi:10.1038/nchem.2491
http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2491.html
Feng等人采用外延生长的策略，实现了在Ag(111)基底表面生长不同周期排列结构的两种二维硼纳米片。该材料具有良好的化学惰性，不易被氧化，有望在电子器件中得到应用！（微信公众号：纳米人）
