Using deep eutectic solvents to pretreat corncob for the fabrication of sustainable lignocellulose hydrogels

Using agricultural wastes as raw materials to manufacture high value-added materials with green and economical processes is of great significance. In this study, corncob processed by deep eutectic solvents (DESs) pretreatment (80–130 °C) can be successfully prepared into lignocellulose-based hydrogels (LCHs) by a facile and green ZnCl 2 /CaCl 2 solvent system. An appropriate amount of lignin can be well dispersed and filled in the structure of LCHs, thus improving the mechanical properties of the hydrogel. The hydrogel using 120 °C pretreated corncob as starting material reached the best tensile stress (144.4 kPa) and compressive stress (401.4 kPa). Due to the excellent flexibility and the presence of a large number of metal ions , the hydrogels prepared from the 120 °C pretreated corncob were assembled into a capacitor and got an energy density of 110.2 Wh/kg at the power density of 495.0 W/kg. In short, this study provides a simple and green method to prepare LCHs and a novel efficient utilization route of the corncob.