Lightweight, Elastic, and Superhydrophobic Multifunctional Organic-Inorganic Fibrous Aerogels for Efficient Oily Wastewater Purification and Electromagnetic Microwave Absorption

Lightweight and robust aerogels with multifunctionality are highly desirable to meet the technological demands of current society. Herein, we designed lightweight, elastic, and superhydrophobic multifunctional organic-inorganic fibrous hybrid aerogels which were assembled with organic aramid nanofibers and inorganic hierarchical porous carbon fibers. Thanks to the organic-inorganic fiber hybridization strategy, the optimal aerogels possessed remarkable compressibility and elasticity. Benefiting from the microscopic hierarchical porous structure of carbon fibers and the macroscopic macroporous lamellar structure of aerogels, the optimal aerogels exhibited superb lightweight property, conspicuous electromagnetic microwave absorption ability, and outstanding oily wastewater purification capacity. As for electromagnetic microwave absorption, it achieved a strong reflection loss of -41.8 dB, and the effective absorption bandwidth reached 6.86 GHz. Besides, the oil adsorption capacity for trichloromethane reached as high as 93.167 g g^-1 with a capacity retention of 95.6% after 5 cycles. Meanwhile, it could act as a gravity-driven separation membrane to continuously separate trichloromethane from a trichloromethane-water mixture with a high flux of 7867.37 L·m^-2·h^-1, even for surfactant-stabilized water-in-n-heptane emulsions of 3794.94 L·m^-2·h^-1. Such a strategy might shed some light on the construction of multifunctional aerogels toward broader applications.