Facile, Noncovalent Decoration of Graphene Oxide Sheets with Nanocrystals

Facile dry decoration of graphene oxide sheets with aerosol Ag nanocrystals synthesized from an arc plasma source has been demonstrated using an electrostatic force directed assembly technique at room temperature. The Ag nanocrystal-graphene oxide hybrid structure was characterized by transmission electron microscopy (TEM) and selected area diffraction. The ripening of Ag nanocrystals on a graphene oxide sheet was studied by consecutive TEM imaging of the same region on a sample after heating in Ar at elevated temperatures of 100 degrees C, 200 degrees C, and 300 degrees C. The average size of Ag nanocrystals increased and the number density decreased after the annealing process. In particular, migration and coalescence of Ag nanocrystals were observed at a temperature as low as 100 degrees C, suggesting a van der Waals interaction between the Ag nanocrystal and the graphene oxide sheet. The availability of affordable graphene-nanocrystal structures and their fundamental properties will open up new opportunities for nanoscience and nanotechnology and accelerate their applications.