Cellulose aerogels achieve excellent absorption of waste oil and organic pollutant, which has received lots of attention recently. It is still a big challenge to obtain aerogels with both high cost-effectiveness and advanced oil absorption performance, since it is a time-consuming, and environmentally unfriendly process to obtain cellulose, compared with direct usage of natural fibers. In this manuscript, we develop highly porous and hydrophobic kapok/microfibrillated cellulose (MFC) aerogels with a dual-scale hierarchically porous structure at micro-level as cost-effective, sustainable, and floating superabsorbents via simple vacuum freeze-drying and surface modification. Kapok, a natural hollow fiber, has been recently considered as a new sustainable resource for oil cleanup. By partially replacing MFC with chopped kapok fibers in MFC aerogels (MMAs), the resultant kapok/MFC aerogels (KCAs) exhibit ultralow density (5.1 mg/cm^-3), ultrahigh porosity (99.58%) and hydrophobicity (140.1°) leading to advanced oil sorption (130.1 g/g) that is 25.3% higher than that of MMAs. In addition, these KCAs can rapidly and selectively absorb waste oil from oil-water mixture with ultrahigh absorption ability of 104-190.1 g/g, which is comparable to other environmentally unfriendly and high-cost aerogels. Furthermore, the KCAs own excellent reusability and sustainability. These benefits enable the KCAs a suitable alternative to clean oil spills.

纤维素气凝胶可以很好地吸收废油和有机污染物，最近受到了广泛的关注。获得既具有高成本效益又具有先进的吸油性能的气凝胶仍然是一个巨大的挑战，因为与直接使用天然纤维相比，这是一种耗时且对环境不友好的获取纤维素的方法。在本手稿中，我们通过简单的真空冷冻干燥和表面改性技术，开发了具有双重规模的多层多孔结构的高孔隙度和疏水性木棉/微纤化纤维素（MFC）气凝胶，具有成本效益，可持续性和漂浮性。木棉，一种天然的中空纤维，最近被视为一种新的可持续石油清洁资源。^-3），超高孔隙率（99.58％）和疏水性（140.1°）导致进阶油吸附（130.1 g / g），比MMA高25.3％。此外，这些KCA可以从油水混合物中快速选择性地吸收废油，具有104-190.1 g / g的超高吸收能力，可与其他对环境不利且成本高昂的气凝胶媲美。此外，KCA具有出色的可重用性和可持续性。这些优点使KCA成为清洁漏油的合适替代品。