For expanding applications of spongy graphene aerogels (GAs) cost-effectively, we report a marriage of the two-step hydrothermal reduction and atmospheric drying method to fabricate a spongy CNC-graphene aerogel (CNG) with oil/water selectivity and tunable mechanical strength by a low-cost and straightforward approach. The reduced graphene oxide (rGO) with CNC by the ice-templated method can give rise to forming the hierarchical structure of hybrid GAs within the PUS network. Meanwhile, the fractured structure of PUS with a pre-compressive step arouses more versatility and durability, involving its selective and high-volume absorbability (up to 143%). The enhanced elastic modulus and more significant swelling effect than pure sponge materials give it a high potential for durable wastewater treatment.
Keywords: cellulose nanocrystals; graphene aerogel; oil-absorption.