Construction of ZnO@PDA core-shell nanoparticle in antimicrobial nanofibril aerogel for sustainable oil-water separation

As global environmental pollution intensifies, the large-scale production of oil-contaminated wastewater has made oil-water separation technology a hot topic in water treatment. Nanocellulose aerogels are characterized by their low weight, high porosity, and exceptional adsorption capabilities, which make them highly efficient for absorbing oil spills and organic pollutants. However, their limited environmental compatibility and structural instability restrict their broader use. Here, the self-polymerizing ability of polydopamine (PDA) is utilized to coat zinc oxide (ZnO) nanoparticles, creating core-shell structures. The adhesive properties of PDA are used to firmly attach nanoparticles to a stable scaffold made of cellulose nanofibrils (CNFs) and poly(vinyl alcohol)(PVA) to form robust composites. To enhance structural hydrophobicity, octadecyltrimethoxysilane (OTMS) was incorporated, yielding the OTMS/ZnO@PDA/PVA/CNF composite aerogel. The material exhibits adsorption capacity (up to 79.39 g/g) for diverse oils, with 97.0 % separation efficiency under gravity-driven conditions and continuous separation capability under external forces. Critically, ZnO@PDA integration confers exceptional antibacterial activity, achieving 99.64 % sterilization. This work advances novel oil/water separation materials with transformative potential for sustainable industrial wastewater treatment and marine oil-spill remediation.