Natural sponge-like wood-derived aerogel for solar-assisted adsorption and recovery of high-viscous crude oil

An efficient collection and recovery of high-viscous crude-oil from oil spillage through an environmental-friendly way is extremely important for water remediation. Herein, a new material of thermally-reduced graphene-oxide coating and decoration of hydrophobic-layer over a compressible wood-sponge was proposed as an adsorbent. Owing to the preferable photothermal conversion, an in-situ solar-assisted thermogenesis process could increase the temperature to 88 °C within 100 s under 1 sun illumination and decrease the viscosity of crude-oil for easy adsorption. The fabricated adsorbent exhibited great performances in separation and adsorption (7.28 g/g–0.801 g/cm3) of oil-spill; with fully active-collection of 50 mL crude-oil within 20 min. Numerical modeling was also employed to gain an in-depth understanding of the adsorption and regeneration processes. The temperature gradient and structural dots subjected to compression stress for both photothermal induced adsorption and compressible recovery of crude oil were investigated as the dominant factors. The adsorbent also exhibited satisfactory adsorption and separation capacities for common light oils and heavy oils. Moreover, the adsorbent could be employed for feasible adsorption in semi-open seawater-environment under light, showing potential for practical treatment of offshore oil-spillage. This work designed a potential route to overcome the dilemma of crude-oil adsorption, due to its inherent high-viscosity, through in-situ photothermal thermogenesis using environment-friendly materials derived from natural wood. The knowledge obtained from this work would help in developing novel adsorbents with applied and ecological merits and further understanding of the related mechanisms.