Low Temperature Hydrothermal Synthesis of Ultra-light and Superelastic Graphene Oxide/Cellulose Aerogels for Absorption of Organic Liquids

Two-dimensional (2D) graphene oxide (GO) nanosheets and 1D 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TOCN) were assembled into GO/TOCN aerogels via a low temperature hydrothermal and freeze-drying process. The as-prepared GO/TOCN aerogels exhibited interconnected 3D network microstructures, a low density of 6.8 mg/cm³, a high porosity up to 99.2% and excellent mechanical flexibility. The high porosity in conjunction with their hydrophobicity (contact angle of 121.5°), allowed the aerogels to absorb different organic liquids with absorption capacities up to 240 times of their own weight, depending on the density of the liquids. These results indicated that the aerogels were excellent candidates as sorbent materials for the clean-up of organic liquids. After five absorption-desorption cycles, the absorption capacity of the TOCN carbon aerogels could be regenerated up to 97% of the initial absorption capability, which demonstrated their excellent recyclability.