Low-cost synthesis of high quality graphene oxide with large electrical and thermal conductivities

Abstract

A simple and cost-effective method for synthesizing high quality thermally reduced graphene oxide (TrGO) thin films using Shellac, is presented. The synthesis temperature ranges from 550 °C to 900 °C, and is the sole control parameter to obtain a carbon content as high as 97 atomic percentage. For TrGO synthesized at 900 ˚C, its XPS, Raman, and TEM data indicate a large portion of sp2 hybridized carbon atoms and large crystal sizes (~1 µm), which resulted in very high electrical and cross-plane thermal conductivities, 2488 S/cm and 1.3 W/m-K, respectively. Furthermore, this high electrical conductivity of TrGO was observed to remain unaffected under mechanical stress 10 times higher than that completely broke solution-processed reduced graphene oxide (rGO) films, promising its potential for robust, transparent, and cost-effective conductive coating.