Lightweight, robust, and antimicrobial cellulose nanofibril aerogels decorated with TiO2@PDA core–shell nanoparticles for highly efficient oil–water separation

Leaks during oil extraction, wastewater containing organic solvents from industrial production and oily wastewater from daily life pose a great threat to the ecosystem and human life, which makes the research and development of oil–water separation materials imminent. Nanocellulose aerogels possess lightweight properties, high porosities, and excellent adsorption capabilities, making them efficient adsorbents for the removal of oil spills and organic pollutants. A novel method is presented utilizing the self-polymerization characteristics of polydopamine (PDA) to encapsulate titanium dioxide (TiO 2 ) nanoparticles, thereby forming core–shell nanoparticles. The unique adhesive properties of PDA play a critical role in the binding of these nanoparticles to a cellulose nanofiber (CNF) scaffold, resulting in a robust composite material. To further enhance the performance of the aerogel, octadecyltrimethoxysilane (OTMS) was incorporated, imparting hydrophobicity to the overall structure, resulting in the OTMS/TiO 2 @PDA/CNF aerogel. This aerogel exhibited outstanding adsorption capabilities and absorbed various light and heavy oils, as well as organic solvents, with an adsorption capacity of up to 59.9 g/g. Under gravity, the separation efficiency of the aerogel reached 96.15 %. An innovative oil collection device was designed for the sustainable separation of pollutants from water to ensure efficient cleanup operations. Furthermore, the aerogel exhibited excellent antibacterial properties with a bactericidal rate of up to 99.14 % and significantly enhanced environmental adaptability. This simple, economical, and environment-friendly method is expected to promote the development of efficient oil/water separation adsorbents and contribute to the control of environmental pollution.