Preparation and photocatalytic activity of nano-TiO₂/regenerated cellulose composite films

Nano-TiO₂/regenerated cellulose films with different titania contents were prepared by directly blending titania powder and cellulose (pulp) in l-allyl-3-methylimidazolium chloride ionic liquid at room temperature. The cellulose was regenerated by water and then dried by supercritical CO₂. The morphology, phase components, structure and thermal property of the films were characterized by SEM, XRD and FTIR. The photocatalytic activities of the films were evaluated for decomposition of the methylene blue under UV light irradiation by PCC-2 photocatalysis evaluation checker. The influencing factors on photocatalytic activity of the films were discussed, such as the content of nano-TiO₂ and the drying methods of supercritical CO₂. The results show that, with the addition of titania, the photocatalytic activity of the films treated by supercritical CO₂ medium is higher than that of films dried in vacuum. The photocatalytic activity of the films increases with the increasing of nano-TiO₂ particles up to 5% and then decreases with the increasing of TiO₂ content.