Production of graphene from graphite oxide using urea as expansion–reduction agent

Graphene sheets were produced from graphite oxide using a simple two-step process. First, graphite oxide (GO) is well mixed with an expansion–reduction agent, such as urea, that decomposes upon heating to release reducing gases. Second, the mix is heated in an inert gas environment (e.g. N2) for a very short time to a moderate temperature (ca. 600 °C). Reaction temperature selection should be consistent with the decomposition temperature of the expansion–reduction agent. Upon cooling, graphene can readily be collected as the solid byproduct. Graphene samples were characterized by XRD, TEM, EELS, SEM, Raman Spectroscopy and the GO and urea mixtures decomposition-reduction process studied by TGA/DSC analysis. This graphene generation process is rapid, inexpensive and easy to scale up.