Super-elastic and mechanically durable MXene-based nanocomposite aerogels enabled by interfacial engineering with dual crosslinking strategy

Recently, MXenes have attracted considerable attention owing to their unique physical and chemical properties. Construction of MXenes to three-dimensional (3D) porous aerogel structures can play a critical role in realizing the profound implications of MXenes, especially for environmental remediation. Nevertheless, developing mechanically robust MXene-based aerogels with reversible compressibility under harsh conditions, such as liquid environments, remains challenging due to the insufficient interfacial strength between MXene nanosheets. Herein, 3D porous MXene-based nanocomposite aerogels are developed by dual physical and chemical crosslinking strategy with poly(vinyl alcohol) and formaldehyde in this study. The developed MXene-based nanocomposite aerogels with designed interfacial engineering exhibit outstanding structural stability and extremely high reversible compressibility up to 98% strain as well as unprecedented mechanical durability (2000 cycles at 50% strain) in water environment. Moreover, the aerogels show adaptable compressibility when exposed to different solvents, which is explained with the Hansen solubility parameter. Thanks to their high compressibility in water, the robust MXene-based aerogels exhibit excellent methylene blue adsorption performance (adsorption capacity of 117.87 mg·g⁻¹) and superior recycling efficiency (89.48% at the 3^rd cycle). The porous MXene-based nanocomposite aerogels are also demonstrated with outstanding thermal insulation capability. Therefore, by synergistically taking their porous structure and super elasticity in liquid environment, the MXene-based aerogels show great promise in diverse applications including adsorption and separation, wastewater purification desalination, and thermal management.