WO3对TiO2粉体晶型转变的影响

Influence of WO3 Additive on Crystallite Structural Transformation of TiO2 Powders

摘要:

以TiO2为原料，通过引入WO3添加剂，经不同温度煅烧后得到钨掺杂的TiO2粉体。利用XRD和SEM等测试手段，研究煅烧温度、WO3引入量对TiO2粉体晶型转变的影响，并对其机制进行探讨。结果表明：WO3促进了TiO2从锐钛矿向金红石的转变，降低了TiO2的晶型转变温度，随着WO3引入量的增加，促进作用增强。引入的WO3以两种形式促进TiO2的晶型转变：一种是Wn+进入TiO2晶格置换Ti4+而促进了晶型转变；另一种是WO3和TiO2发生氧化还原反应，促进了TiO2的晶型转变。

关键词:WO3;TiO2;晶型转变

Abstract:

The tungsten-doped TiO2 powders were prepared by calcination process at different temperatures, with TiO2 as starting materials and WO3 as additive. The XRD and SEM were used to investigate the influence of calcination temperatures and the content of WO3 on the phase transformation of TiO2 powders. Moreover the transformation mechanism was discussed. The results show that the phase transformation from anatase to rutile of TiO2 powders is mainly attributed to the additive WO3. WO3 can promote the phase transformation and lower the transformation temperatures. The phase transformation of TiO2 are caused by two aspects of WO3, one is the replacement of some Ti4+ by Wn+ in TiO2 crystal lattice, and the other is the redox reaction between WO3 and TiO2. The replacement of Ti4+ by Wn+ during the redox reaction is believed to be the major factor influencing the phase transformation.

Key words:WO3; TiO2; crystallite structural transformation