Production of superhydrophobic cardboard-based aerogel for effective oil recovery

While biomass-derived aerogels have shown promising potential for oil spill remediation, the use of harmful solvents during their production processes, with consequent environmental impacts, remains a significant hurdle. This research addresses the challenge by presenting a quite simple method for creating a robust and superhydrophobic dual-pore structured aerogel from readily available cardboard waste for efficient oil recovery. The aerogel is crafted through a freeze-drying process that generates a network of interconnected random and lamellar pores. Subsequent crosslinking with Ca²⁺ ions and a silanization reaction enhance the material's resilience and promote hydrophobicity. These combined treatments endow the final aerogel with reliable mechanical integrity, good thermal stability, and fire-retardant properties. Notably, the adsorbent demonstrates exceptional oil recovery capabilities, with a rapid adsorption time of 1–2 s and a high saturation adsorption capacity ranging from 16.1 to 29.5 g g⁻¹. Furthermore, the aerogel exhibits excellent reusability, maintaining its oil recovery performance even after multiple cycles.