Structural and morphological behavior of TiO2 rutile obtained by hydrolysis reaction of Na2Ti3O7

Abstract

The structural transformation behavior of Na2Ti 3O7 by hydrolysis was investigated in mild and strong acidic aqueous medium. Compared with K2Ti4O9, Na2Ti3O7 exhibits quite different structural and morphological transformation behavior despite their similar layered structural characteristics. TiO2(B) obtained by heat treatment of H2Ti3O7 at 350°C transforms to rutile TiO2 at 900°C. This temperature is much lower than 1200 °C, the temperature for anatase to rutile transition when K2Ti 4O9 is used as a starting titanate. A rectangular rod shape and size of TiO2(B) particles obtained from Na 2Ti3O7 is also different from a fibrous structure of TiO2(B) prepared using K2Ti4O 9. Rutile crystals of 100 nm diameter with a corn-like morphology and large surface area are directly obtained when the hydrolysis of Na 2Ti3O7 is carried out at 100°C in a strong acid solution. The structure of starting titanates and the hydrolysis conditions are an important factor to decide the particle size and morphology of TiO 2(B) and TiO2.