Preparation and optical properties of sonication-assisted nitrogen doped graphene oxide sheets

The graphene and graphene oxide sheets were prepared from directly exfoliated and Hummer’s method. Nitrogen doping was applied with the assistance of ultra-sonicator to achieve doping via a simple, low-cost aqueous route. The size of graphene and graphene oxide sheets was examined by transmission electron microscopy with a size of several micrometer. The doping phenomenon was achieved by the addition of aqua ammonia and the analysis were examined by Raman microscopy. The approve of N-doping was got with the appearance of G′ band. The existence of nitrogen element were further examined by energy dispersive spectroscopy.