Influence of WO3 Additive on Crystallite Structural Transformation of TiO2 Powders

Abstract The tungsten-doped TiO 2 powders were prepared by calcination process at different temperatures, with TiO 2 as starting materials and WO 3 as additive. The XRD and SEM were used to investigate the influence of calcination temperatures and the content of WO 3 on the phase transformation of TiO 2 powders. Moreover the transformation mechanism was discussed. The results show that the phase transformation from anatase to rutile of TiO 2 powders is mainly attributed to the additive WO 3 . WO 3 can promote the phase transformation and lower the transformation temperatures. The phase transformation of TiO 2 are caused by two aspects of WO 3 , one is the replacement of some Ti 4+ by W n + in TiO 2 crystal lattice, and the other is the redox reaction between WO 3 and TiO 2 . The replacement of Ti 4+ by W n + during the redox reaction is believed to be the major factor influencing the phase transformation.