Preparation of graphene nanosheets through repeated supercritical carbon dioxide process

In this study, we reported that the supercritical carbon dioxide (scCO2) process is potentially useful for exfoliation of graphite to provide less-damaged graphene nanosheets (GNs). Also, the repeated scCO2 process was found to further reduce the thickness of the exfoliated GNs, which shows the possibility of producing thickness-controlled GNs by varying numbers of scCO2 process.

► We fabricated less-damaged graphene nanosheets, which have higher conductivity than chemically reduced graphene oxides, through supercritical carbon dioxide process.
► We optimized processing condition by varying applied pressure and stirring time.
► The thickness of graphene nanosheets can be reduced by repeated supercritical carbon dioxide process, which shows the possibility of production of thickness-controlled GNs by number of process.