Fe^3＋掺杂纳米TiO2的表征及其光催化性能的研究

目的]提高TiO2的可见光响应和光催化活性。方法]采用溶胶凝胶法制备掺铁纳米TiO2粉体,进而研究掺铁TiO2的光催化活性。结果]450℃煅烧后掺铁TiO2出现了很明显的TiO2特征衍射峰,且峰形尖锐,结晶良好,均没有出现铁的掺杂新相。随着掺铁量的提高,TiO2的粒径逐渐减小,当掺杂量为0.4%时,TiO2的粒径最小,减少至纯TiO2的45%。掺铁抑制了锐钛矿向金红石矿的转变。随着焙烧温度的升高,TiO2的粒径逐渐增大。用溶胶-凝胶法制备的TiO2均为纳米级,基本成球形颗粒。纯TiO2粒子分布不是很均匀,团聚现象明显;掺铁TiO2颗粒分布均匀,没有明显的团聚现象。掺铁使TiO2在紫外灯和太阳光下的降解性能都有着不同程度的提高。结论]溶胶-凝胶法制备的掺铁纳米TiO2细化了晶体晶粒,抑制了锐钛矿向金红石矿的转变。

Characterization of Nanoparticle TiO_2 Doped with Fe~(3+) and Research on Its Photocatalytic Activity

Objective]The study aim to enhance the response to visible light and photocatalytic activity of TiO2.Method]The nanometer TiO2 powder doped with Fe3+ was prepared by so-gal process and its photocatalytic activity was studied.Result]The TiO2 doped with Fe3+ showed obvious characteristic diffraction peaks of TiO2 after it was calcinated at 450 ℃,the peak form was sharp,crystallization was well and there was no new phase of Fe3+.As the doping amount of Fe3+ was increased,the particle diameter of TiO2 was decreased gradually.When the doping amount of Fe3+ was 0.4%,the particle diameter of TiO2 was smallest and it was decreased to 45% of the particle diameter of pure TiO2.The doping of Fe3+ inihibted the transform from anatase to rutile.As the calcination temperature was increased,the particle diameter of TiO2 was increased gradually.All the TiO2 prepared by sol-gal process was nanometer and most of them were spheroidal particles.The distribution of pure TiO2 particles was not very uniform and their agglomeration was obvious.The distribution of TiO2 particles doped with Fe3+ was uniform and there was no agglomeration.The doping of Fe3+ enhanced the degradation efficiency of TiO2 under UV lamp and sunlight to different degrees.Conclusion]The nanometer TiO2 doped with Fe3+,which was prepared by sol-gal process,refined grain of crystal and inhibited the transform from anatase to rutile.