Hydrothermal Synthesis of Polymorphic Titania and their Structural Evolution from Potassium Titanate Whisker

The hydrothermal synthesis of polymorphic titania crystals and their structural evolution from potassium titanates,K_2Ti_6O_(13),K_2Ti_4O_9 and K_2Ti_8O_(17) whiskers,were studied systematically. Dispersed,regular twinning rutile TiO_2 was firstly generated by hydrothermally treating K_2Ti_6O_(13) whisker in an acid medium.The crystal phase and morphologies varied with different reaction tem- peratures and time in diverse mediums were investigated using XRD,SEM and TEM.The results indicate that the weak-binding crystallographic planes are the key factors of the crystal transformation in the hydrothermal system.The transformation from K_2Ti_6O_(13) to the twinning rutile is achieved via rearranging structural units on the {100} or {201} plane.