Seamless Graphene-Seal-Wrap as a Removable Protective Cover for Two-Dimensional Materials

The emerging two-dimensional (2D) materials have attracted explosive research interest, because of their unique properties and broad applications. However, the instability of typical 2D materials (for instance, black phosphorus (BP)) places restrictions on their practical applications. It is of great importance to develop effective sealing materials to protect these unstable but promising 2D materials. Herein, we develop a highly efficient and removable graphene-seal-wrap (GSW) based on large-area grain-boundary-free graphene films. As a proof of concept, the air- and moisture-sensitive BP was successfully protected by the as-developed GSW. The results reveal that BP can remain stable even under high humidity conditions for up to 18 days, while the bare ones are easily oxidized. More importantly, the graphene sealing layer can be facilely removed without affecting the underlying BP surface, making it an ideal sealing film. This GSW can promptly provide an air- and moisture-proof film for handling unstable 2D materials, paving an avenue for their device fabrication and practical applications.