Fabrication of flexible metal-nanoparticle films using graphene oxide sheets as substrates.

Graphene-based sheets that possess a unique nanostructure and a variety of fascinating properties are appealing as promising nanoscale building blocks of new composites. Herein, graphene oxide sheets are used as the nanoscale substrates for the formation of silver-nanoparticle films. These silver-nanoparticle films assembled on graphene oxide sheets are flexible and can form stable suspensions in aqueous solutions. They can also be easily processed, forming macroscopic films with high reflectivity. Raman signals of graphene oxide in such hybrid films are increased by the attached silver nanoparticles, displaying surface-enhanced Raman scattering activity. The degree of enhancement can be adjusted by varying the quantity of silver nanoparticles on the graphene oxide sheets.