Sustainable Cellulose Aerogels Derived from Sugarcane Bagasse: Synthesis, Characterization, and Oil Adsorption Performance

A bio-based cellulose aerogel was successfully synthesized from sugarcane bagasse, an abundant agricultural by-product, using sodium alginate and zinc acetate as cross-linking agents. The aerogel was prepared through a sol–gel process followed by freeze-drying, resulting in an ultralight three-dimensional porous structure. The obtained aerogel exhibited a low bulk density of approximately 0.077 g/cm³ and high porosity, which are favorable for oil adsorption. Characterization by FTIR, Raman, XRD, and FE-SEM/EDX confirmed the presence of abundant functional groups, amorphous structure, and interconnected pores favourable for adsorption. The aerogel exhibited high oil adsorption capacities, reaching 7.98 g/g for cooking oil and 6.83 g/g for diesel. Adsorption kinetics were well described by the pseudo-second-order model, suggesting that surface-related interactions associated with functional groups and ionic cross-linking govern the adsorption process, with chemisorption being the dominant mechanism. These results demonstrate that sugarcane bagasse-derived cellulose aerogel is a sustainable and efficient candidate for oil spill remediation.