A Degradable Photo-Thermal Aerogel with Biomimetic Structure and Selective Wettability for High-Throughput Recovery of Viscous Crude Oil

Adsorbents with super-wettability are deemed as an ideal candidate in treatment of oil spills, however, the recovery of high-viscous crude oil faces the difficulties of low adsorption efficiency and the recycling burden from waste adsorbents. In this study, inspired by the substances transport channel of stem from colocasia gigantea, a photo-thermal and flame-retardant aerogel with super-hydrophobicity/super-oleophilicity exhibits a high-throughout recovery of 548 kg m⁻²h⁻¹ toward solid-paste crude oil under the solar illumination of 0.1 W cm⁻². These properties are attributed to its optimized aperture distribution and vertically aligned bio-channel structure, which can be controlled by adjusting freeze-drying process and feeding ratios of aerogel skeleton between cellulose and chitosan. Significantly, the self-decomposition of as-prepared aerogel is demonstrated after burying it in a soil environment, showing the remarkable natural degradability. Additionally, the aerogel maintains a water rolling angle of 8 ± 1° even after the 100 cycles compression test and the immersion in organic solvent (120 h) and corrosive solution (24 h), demonstrating its good mechanochemical durability. This work endows the aerogel adsorbent with selective super-wettability, degradeability, photo-thermal conversion, and flame-retardancy, which are highly demanded in multi-scenarios oil recovery.