微波辅助制备掺铁纳米TiO_2溶胶及其性能研究

Photocatalysis activity and preparation of Fe-doped TiO_2 hydrosol by microwave irradiation peptization

为了进一步提高纳米二氧化钛溶胶的光催化活性,采用微波辅助胶溶的方法制备了不同铁掺杂量的纳米二氧化钛(Fe-TiO2)溶胶,并以偶氮染料活性艳红X-3B为目标物,分别考察不同铁掺杂量对纳米Fe-TiO2溶胶光催化活性的影响,研究表明原子数分数为0.05%的Fe3+掺杂量最佳;对Fe-TiO2溶胶、TiO2溶胶及P25(Degussa纳米TiO2)悬浮液的光催化活性进行对比,结果表明:TiO2溶胶与P25悬浮液光催化活性相当,而Fe-TiO2溶胶较前两者具有更高的光催化活性.采用XRD、DLS、AFM和DRS的分析方法对溶胶进行表征,结果表明:微量铁掺杂对纳米TiO2的晶型及粒径分布无显著影响;但铁掺杂可以使纳米TiO2对紫外光的吸收有较大程度的增强,同时吸收边带发生了较明显的红移.铁掺杂对于提高纳米TiO2溶胶的光催化活性和拓展其光吸收范围均具有显著的积极的作用.

To further improve the photocatalysis property of nano-TiO2 hydrosol,Fe-doped TiO2 hydrosol（Fe-TiO2 sol） was prepared by microwave irradiation peptization.The photocatalytic activity of the Fe-TiO2 hydrosol was evaluated by the decomposition of azo dye（X-3B） in liquid phase under UV light illumination,and was compared with that of pure TiO2 hydrosol and that of commercial titania（Degussa P25）.Results reveal that the Fe-TiO2 hydrosol has the best photocatalytic activity.It was characterized XRD,DLS,AFM and DRS.The results show that the structure and particle size distribution of Fe-TiO2 do not change compared with those of the pure TiO2 hydrosol;but the absorbance of Fe-TiO2 particles exhibits a progressive increase in the UV-light region,and Fe modified TiO2 extends its absorption sidebands about 20 nm to the direction of long wavelength.All results suggest that Fe modified TiO2 can improve the photocatalytic activity of nano TiO2 hydrosol.