Glycol-Thermal Continuous Flow Synthesis of Graphene Gel

[Image: see text] Hydrothermal treatment of graphene oxide (GO) aqueous dispersion has been extensively applied to create graphene (a.k.a., chemically modified graphene, or reduced GO) hydrogels, which were dried to yield high-density graphene monoliths and powders with promising potential for electrochemical energy storage applications. Here, we demonstrated a glycol-thermal route that allows the preparation of a graphene gel at around 150 °C, which is below the boiling point of ethylene glycol (EG) and thus eliminates the need for a sealed pressurized reaction vessel. As a result, flow synthesis can be achieved by flowing a GO dispersion in EG through a Teflon tube immersed in a preheated oil bath for continuous production of a graphene gel, which, upon drying, shrinks to yield a densified graphene solid.