rGO/BC nanocomposite aerogels exhibit recyclable adsorption of organic solvents and oils with enhanced flame resistance

In this study, a simple and eco-friendly method was developed to prepare nanocomposite aerogels composed of bacterial cellulose (BC) and graphene oxide (GO) via freeze-drying. Nanocomposite aerogels with different ratios of BC to GO 50:50, 80: 20, and 90: 10 were synthesized. Various preparation methods and conditions were employed including room temperature, reflux, hydrothermal treatment, reduction in a hydrogen furnace, and chemical reduction with different reducing agents (hydrazine, ethylenediamine, and ascorbic acid) and using glutaraldehyde as a linker. The structure and morphology of the nanocomposites were characterized using FT-IR, Raman spectroscopy, UV–Vis, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and Brunauer–Emmett–Teller (BET) surface area and porosity analysis. Thermal stability was assessed using thermogravimetric analysis (TGA). The performance of aerogels in adsorbing various organic solvents—such as cyclohexane, dichloromethane, dimethyl sulfoxide, and dimethylformamide as well as oils like pump oil and olive oil, was investigated. The rGO /BC-90G nanocomposite exhibited the highest adsorption capacity, up to 116 g of organic liquids (dichloromethane) per gram of aerogel, and significantly greater surface area (188 m 2 . g -1 ) than other prepared aerogels. In this study, the hydrophobicity of aerogels and their functions as thermal insulation were also investigated. Among the as-prepared composites, rGO/BC-90H 2 demonstrated pronounced hydrophobicity and rGO/BC-90G exhibited superior thermal stability, while rGO/BC-50H1 showed distinct decomposition behavior related to partial reduction. Notably, the aerogels could be reused for up to five adsorption cycles while retaining a high fraction of their initial adsorption capacity, highlighting their potential for sustainable adsorption applications.