Aqueous colloids of graphene oxide nanosheets by exfoliation of graphite oxide without ultrasonication

Aqueous colloids of graphene oxide nanosheets were produced from exfoliation of graphite oxide using a magnetic stirrer and heat treatment in the absence of ultrasonication. Laser particle measurements showed that the particle size distribution of graphite oxide dispersed in de-ionized water was significantly influenced by treatment time indicating an increasing exfoliation level of graphite oxide. Atomic force microscopy (AFM) confirmed that single-layer graphene oxide nanosheets with a thickness of similar to 1 nm were obtained after 72 h of magnetic stirring and heat treatment. These findings provide a new methodology for preparation of single-layer graphene oxide nanosheet colloids.