Solid Carbon Sources Lead To Graphene

Organic polymers and other common solid carbon compounds can be converted to graphene, according to researchers at Rice University who developed a synthetic method for preparing the atom-thin form of carbon (Nature, DOI: 10.1038/ nature 09579). Graphene is typically prepared either by peeling apart tiny graphite flakes or by chemical vapor deposition methods. The vapor-based technique, which generally involves decomposing methane or ethylene on metal surfaces, is suitable for producing sheets measuring tens of square inches (C&EN, July 5, page 31). That method, however, excludes the possibility of using nongaseous feedstocks. Zhengzong Sun, Zheng Yan, James M. Tour, and coworkers demonstrated that poly(methyl methacrylate), the polycyclic aromatic hydrocarbon fluorene, and even table sugar (sucrose) can be reduced to monolayer graphene by depositing the solids on copper and heating to 800 °C in a dilute hydrogen atmosphere. That temperature, which is some 200 °C lower than what is prescribed by other methods, is cool enough to be compatible with silicon-processing methods. Films made by the new method were incorporated into working electronic devices, the team reports.