Bionic Aerogel with a Lotus Leaf-like Structure for Efficient Oil-Water Separation and Electromagnetic Interference Shielding

Abstract

Increasing pollution from industrial wastewater containing oils or organic solvents poses a serious threat to both the environment and human health. Compared to complex chemical modifications, bionic aerogels with intrinsic hydrophobic properties exhibit better durability and are considered as ideal adsorbents for oil-water separation. However, the construction of biomimetic three-dimensional (3D) structures by simple methods is still a great challenge. Here, we prepared biomimetic superhydrophobic aerogels with lotus leaf-like structures by growing carbon coatings on Al2O3 nanorod-carbon nanotube hybrid backbones. Thanks to its multicomponent synergy and unique structure, this fascinating aerogel can be directly obtained through a simple conventional sol-gel and carbonization process. The aerogels exhibit excellent oil-water separation (22 g·g−1), recyclability (over 10 cycles) and dye adsorption properties (186.2 mg·g−1 for methylene blue). In addition, benefiting from the conductive porous structure, the aerogels also demonstrate outstanding electromagnetic interference (EMI) shielding capabilities (~40 dB in X-band). This work presents fresh insights for the preparation of multifunctional biomimetic aerogels.

Bioinspired aerogels: ingenious structure, remarkable performance, and versatile applications

“…10e). 133 As shown in Fig. 10f, CACAs exhibit rod-like micronano structures similar to the surface of lotus leaves.…”

Biomass Chitosan-Based Tubular/Sheet Superhydrophobic Aerogels Enable Efficient Oil/Water Separation

“…Moreover, due to the intrinsic fragility and internal chaotic porous structure, biomass materials are prone to have a collapse of internal structure and a swelling-then-dissolution feature when used in a water environment, which in turn severely restricts the biomass aerogel from the oil-water separation application. In nature, some natural materials like seaweed, lotus stems, and wood show an orderly, organized interior and a regular structure, hence demonstrating extraordinary mechanical properties [ 21 , 22 ]. Derived from conventional freeze-drying techniques, directional freeze-drying technology generates a temperature gradient in a single direction, which promotes the directional growth of ice crystals in the precursor to form an oriented porous structure along the temperature gradient after freeze-drying [ 23 , 24 , 25 ].…”

Superhydrophobic/Superoleophilic PDMS/SiO2 Aerogel Fabric Gathering Device for Self-Driven Collection of Floating Viscous Oil

“…Porous absorbent materials with water repellency such as sponges, foam materials, rubber, carbon-based materials, and chemosynthesis adsorbents have drawn much attention to dealing with floating oil assigned to their prominent adsorption characteristics and extrusion property [21][22][23]. The materials could spontaneously and selectively adsorb oil from the water surface due to their lipophilicity and water resistance, usually possessing excellent adsorption capacity and exceptional separation efficiency.…”