Highly tough cellulose/graphene composite hydrogels prepared from ionic liquids

• Stable and homogeneous graphene IL solution was obtained without using any stabilizer.
• The composite hydrogels were easily prepared by regenerating the cellulose/graphene mixed solution from water.
• The composite hydrogels and aerogels have high mechanical strength and good thermal stability.
• This work provides a simple and green method to combine the extraordinary performances of graphene with the multifunctional properties of cellulose-based hydrogels.

Highly tough cellulose/graphene composite hydrogels (CGH) were successfully prepared by simply regenerating the mixture of wood pulp and reduced graphene oxide (rGO) from their ionic liquid (IL) solution using deionized water as coagulant. Nontoxic and cost-efficient Vitamin C was used as the reducing agent for preparing rGO directly in IL. Significantly enhanced mechanical strength and thermal stability was observed with the CGH in comparison with pure cellulose hydrogels (CH), and the mechanical properties of CGH were related with the doping ratio of rGO. Over four times higher compressive Young’s modulus was obtained with 0.5 wt% doping of graphite oxide (GO) in cellulose. This method provides a simple and green method to combine the extraordinary performances of graphene with the multifunctional properties of cellulose-based hydrogels, and thus holding great potential for future applications in the fields of biology and energy.