Super-hydrophobic cotton aerogel with ultra-high flux and high oil retention capability for efficient oil/water separation

Natural biodegradable cotton-based materials are one of the promising materials for oil/water separation. However, the high oil retention ability of the oil/water separation materials benefiting oil transportation and storage is often ignored, and the separation flux of these cotton-based materials is usually unsatisfactory, hindering their applications. In this work, a super-hydrophobic cotton aerogel was prepared through a facile and mild dipping-heating process for oil/water separation. The obtained super-hydrophobic cotton aerogel with high porosity (about 94%), and super-hydrophobic surface (water contact angle as high as 152.7° ± 1.1°, and sliding angle as low as 9.2° ± 0.2°) showed excellent structural strength, allowing them to get an ultra-high separation flux (about 37,000 L m⁻² h⁻¹) as well as a high oil retention ability. This work provides a facile approach to fabricating cost-effectively and environment-friendly materials for efficient oil/water separation.