Controllable fabrication of chitosan-lignocellulose aerogels derived from agricultural waste and their enhanced mechanism in oil-water separation

As oil pollution continues to pose serious environmental threats, the development of efficient and eco-friendly materials for its remediation has become increasingly important. In this study, six types of deep eutectic solvents (DESs) were used to treat corn stalks, yielding cellulose-rich materials that were subsequently combined with chitosan to fabricate aerogels designed for oil–water separation. The resulting aerogels exhibited high oil–water separation efficiency, achieving over 95 % in the initial cycle and retaining efficiencies above 90 % after at least five reuse cycles. They also exhibited excellent mechanical strength, demonstrating 95 % height recovery after 50 compression cycles at 50 % strain, along with stable stress–strain behavior. Furthermore, the aerogels were amphiphilic in air (contact angle < 90°) and superoleophobic underwater (contact angle > 150°), making them highly suitable for efficient oil–water separation. This study is the first to utilize DES-treated cellulose-rich biomass for the fabrication of aerogels. The DES treatment facilitated precise control over the surface properties of the materials. Moreover, the small amount of lignin retained within the biomass contributed to reinforcing the aerogel network, thereby enhancing its mechanical stability. Compared to conventional approaches, this method not only provides an effective solution for mitigating oil pollution but also adds value to agricultural waste. The resulting aerogels surpass many recently reported cellulose-based aerogels in terms of separation efficiency, recyclability, and environmental safety, presenting a promising green technology for water treatment and pollution control.