A wood-based aerogel with hierarchical porous and asymmetric wettability for efficient and robust solar-driven viscous crude oil recovery.

Photothermal-assisted adsorption is an effective strategy for removing high‑viscosity crude oil spills. However, low adsorption rates and contamination of surface photothermal functional layers still greatly restrict the application of oil-adsorbing materials. To address this challenge, we fabricated a functionally segregated wood-based aerogel adsorbent (J/MCCA@CDW) featuring a bottom oleophilic layer with a hierarchical pore structure for fast crude oil adsorption and a top amphiphobic photothermal layer to protect the photothermal effect. Through vacuum impregnation, hydrophobic cellulose aerogel precursor (MCCA) was incorporated into a carboxylated delignified wood (CDW) skeleton to form vertical channels with low pore tortuosity and aerogel micropores with strong capillary force. Benefiting from its unique pore architecture, J/MCCA@CDW exhibits excellent adsorption performance toward high-viscosity crude oil, with an adsorption rate of up to 2.44 kg·m-3·s-1 under 1.0 kW·m-2 illumination. Moreover, owing to this functionally segregated design, the material maintains a surface temperature above 60 ℃ even after 10 adsorption cycles and retains 94% of its initial adsorption capacity, demonstrating superior photothermal stability and reusability. This design strategy overcomes the key drawbacks of traditional photothermal adsorbents (severe contamination, poor recyclability, low efficiency) and provides an innovative route to high-performance solar-driven adsorbents.