Organic Solvent Resistant Nanocomposite Films Made from Self-precipitated Ag/TiO₂ Nanofibers and Cellulose Nanofiber for Harmful Volatile Organic Compounds Photodegradation

Cellulose exhibits outstanding chemical stability, nontoxicity, and renewable ability and is regarded as a candidate for next-generation sustainable materials. After the nanofibrillation of cellulose, cellulose nanofiber (CNF) exhibits unique optical properties, good mechanical strength, and a high aspect ratio. It is suitable to be a matrix for the photocatalysts immobilization and applied in pollutant removal owing to its solvent resistance. Combined with 1D TiO₂, the network structure may be expected and beneficial for the charge transport of TiO₂ nanofibers. In this study, the flexible CNF composites film incorporated with various sizes and morphology of TiO₂ photocatalysts is fabricated. The relationship between the chemical and physical properties of the composite film and morphological features are discussed. The GIWAXS analysis shows that the entanglement of self-precipitated Ag-doped TiO₂ NFs (STNFs) and CNF induce the densely hierarchical stack and regular stacking orientation. For 30 day solvent resistance tests, various CNF composite films show outstanding stability in the acetone and dimethylformamide (DMF). In the photodegradation of methyl orange in ethanol, STNF/CNF film presents a high degradation efficiency of 87% and shows excellent stability of morphology and activity after three cycles. For volatile organic compound degradation, the degradation efficiencies toward methanol and DMF vapor are higher than 90%.