Preparation of porous TiO2 sheets by aqueous tape casting and their photocatalytic activation

Porous titania (TiO(2)) sheets were prepared by aqueous tape casting. In slurry preparation, ammonium polyacrylate, polyvinyl alcohol, and polyethylene glycol were used as dispersant, binder, and plasticizer, respectively. The properties of slurries were characterized by zeta-potential, sedimentation test, and rheological behavior. The influences of sintering temperature on the open porosity, phase composition, and microstructure of the specimens were studied. The open porosity of the specimens ranged from 44% to 58%. The results indicate that the photocatalytic efficiency of specimens is closely related to the phase composition, the open porosity as well as the grain size of TiO(2) sheet. The porous TiO(2) sheets have lower efficiency than TiO(2) powder; however, the porous sheets do not result in the secondary contamination problem.