Explosive Thermal Reduction of Graphene Oxide Based Materials

Graphene Oxide (GO) – a single layer carbon atom sheet covered with various oxygen functional groups, is the main precursor for pristine graphene (G) synthesis in application of many commercial products such as transistors, touch screens, solar panels, and conductive inks. It has been observed that under certain conditions dry form multilayer GO could be energetic and  may undergo violent decomposition, releasing large amounts of heat comparable to known hazardous chemicals or explosives such as TNT. The chemical decomposition reaction occurring is self-sustaining which allows even a small initial reaction to cause an entire bulk GO to react, making it hazardous. If large quantities of bulk GO were to suddenly react, it would pose a serious safety hazard, due to vast heat release. Therefore, it is imperative to understand the behavior before such an event can ever occur. The effects of common GO synthesis process contaminant ions such as Potassium and Sodium as well as treatment with both acid and base on relevant thermodynamic properties were evaluated. Treatment with base was found to destabilize the GO, shifting the violent decomposition reaction onset temperature by approximately 50̊C, but it was also found that the overall heat of decomposition decreased. GO treatments with acid and various salts were found to have no effect on thermal characteristics of the final bulk material. Our findings were backed by measurement of surface functionalities which showed changes in the relative abundances of surface functional groups for different treatments.