纳米TiO2 / 再生纤维素复合薄膜的制备及光催化性能

在1-烯丙基-3-甲基咪唑氯室温离子液体中, 将纳米TiO₂粉末与纤维素浆粕进行溶液共混, 所得纤维素用水再生后, 经过超临界CO₂干燥处理, 制备了不同TiO₂ 含量的纳米TiO₂ / 再生纤维素复合膜。通过扫描电子显微镜(SEM) 、X 射线衍射(XRD) 、傅立叶变换红外光谱( FTIR) 对所得薄膜的形貌、结构进行表征。利用PCC-2 型光催化活性检测仪测试薄膜在紫外光下光催化降解亚甲基蓝的能力, 评价薄膜的光催化活性。讨论了纳米TiO₂ 含量、超临界CO₂ 干燥和真空干燥对薄膜性能的影响。结果表明: 复合膜的光催化活性达到所用TiO₂粉体的90 %; 经超临界CO₂ 干燥处理所得复合膜的光催化活性明显高于真空干燥所得复合膜的活性; 纳米复合膜的光催化活性随TiO₂ 含量的增加先升高后降低, 含量为5 %时光催化活性最高。 

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

Nano-TiO2/regenerated cellulose films with different titania contents were prepared by directly blending titania powder and cellulose(pulp) in 1-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.