Rapid route for synthesis of nano-TiO2 termed graded calcination

To work out the problem of having excessive gelatinising time in the sol-gel method, nano-TiO₂ was prepared through an original approach termed as graded calcination method. The results indicated that the gelatinising time has been shortened from 14-20-days to 6-h as the preparation method changed from the conventional sol-gel way to the new process. Analyses of X-ray diffraction indicate that the TiO₂ sample from graded calcination method shows as a complete anatase. The grain size is much smaller and uniformer, and the lattice distortion and specific surface area are both promoted by the new method. TiO₂ prepared by graded calcination has better absorption capacity in both UV and visible region, and its photocatalytic activity is better than TiO₂ sample made from sol-gel method.