Bacterial cellulose derived monolithic titania aerogel consisting of 3D reticulate titania nanofibers

Monolithic titania (TiO2) aerogel was fabricated by using bacterial cellulose (BC) as the bio-template and preceramic polymer as titanium resource, via freeze-drying and two-step calcination process. As-prepared TiO2 aerogel BCTi-air-2 h possessed low bulk density (0.04 g/cm3) and moderate mechanical strength. SEM images showed that TiO2 aerogel was composed of 3D reticulate TiO2 nanofibers. The anatase crystalline structure of TiO2 with crystal size around several nanometers was revealed by XRD measurements. N2 adsorption/desorption analysis indicated that TiO2 aerogel possessed high specific area (115 m2/g) and macroporous structure, which contributed to the high photocatalytic activity. Most importantly, the monolithic state will ease the usage, recycling, and regeneration of TiO2 aerogel as photocatalyst.