期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2019
卷号：116
期号：42
页码：20844-20849
DOI：10.1073/pnas.1909500116
出版社：The National Academy of Sciences of the United States of America
摘要：Two-dimensional van der Waals materials have rich and unique functional properties, but many are susceptible to corrosion under ambient conditions. Here we show that linear alkylamines n -C m H 2 m +1 NH 2 , with m = 4 through 11, are highly effective in protecting the optoelectronic properties of these materials, such as black phosphorus (BP) and transition-metal dichalcogenides (TMDs: WS 2 , 1T′-MoTe 2 , WTe 2 , WSe 2 , TaS 2 , and NbSe 2 ). As a representative example, n -hexylamine ( m = 6) can be applied in the form of thin molecular monolayers on BP flakes with less than 2-nm thickness and can prolong BP’s lifetime from a few hours to several weeks and even months in ambient environments. Characterizations combined with our theoretical analysis show that the thin monolayers selectively sift out water molecules, forming a drying layer to achieve the passivation of the protected 2D materials. The monolayer coating is also stable in air, H 2 annealing, and organic solvents, but can be removed by certain organic acids..
