Sustainable, Flexible, and Superhydrophobic Functionalized Cellulose Aerogel for Selective and Versatile Oil/Water Separation

Aerogels, as ultralight three-dimensional (3D) highly porous materials, show great superiority in oil and organic pollutant cleanup. Notably, biomass aerogels have also attracted wide interest due to the advantages of huge reserves, low cost, renewability, biodegradation, and nontoxicity to the environment. Herein, a sustainable, flexible, and superhydrophobic functionalized cellulose aerogel, copper nanoparticles-coated cellulose aerogel (Cu/CEA), is reported. The hydrophobic Cu/CEA was simply fabricated by one-step depositing Cu nanoparticles coating on the cellulose fibers extracted from renewable natural sisal in liquid phase followed by freeze–drying. The hydrophobic functionalization approach is facile, cost-effective, and suitable for large-scale production and environmental friendliness, without additional organic hydrophobic modification. The highly porous Cu/CEA as absorbent can selectively and quickly collect oily contaminant, exhibiting high oil absorption capacity and rate, and good recyclability. In addition, it can also act as a thick film to continuously and rapidly separate oil/water mixtures including emulsions, possessing very high separation efficiency and flow rate. Hence, the versatile and high-performance functionalized cellulose aerogel possesses a promising practical application in oily wastewater treatment and pollution remediation.