树叶为模板制备网状TiO_2和Fe_x/TiO_2及光催化活性研究

Leaf as a Template for Reticular TiO_2 and Fe_x/TiO_2:Synthesis,Characterization and Photo-catalytic Activities

以梧桐树叶为模板制备了具有网状结构的TiO2和Fex/TiO2光催化材料.通过扫描电镜(SEM)、X-射线衍射(XRD)、X-射线光电子能谱(XPS)、荧光发射光谱(PL)、紫外-可见吸收光谱(UV-Vis)等对这两类光催化材料的结构和物理性能进行了表征.结果表明,以树叶为模板制得的Fe0.005/TiO2呈网状结构.在600～800℃范围内,随煅烧温度的升高,网状TiO2和Fe0.005/TiO2中锐钛型TiO2的含量减少,Fe3+的掺杂能促进锐钛型向金红石型的转变.与Degussa P25相比,网状TiO2和Fex/TiO2的荧光光谱强度明显减弱,光生电子-空穴对的复合情况得到改善;吸收光谱范围明显红移,禁带宽度有不同程度的缩小.孔雀石绿的光催化降解实验表明,网状TiO2和Fex/TiO2具有比Degussa P25更强的催化活性.光催化活性的稳定性研究表明,网状Fe0.005/TiO2具有良好的稳定性,能多次重复使用.

The reticular TiO2 and Fex/TiO2 photo-catalytic materials were prepared by using the leaves of phoenix tree as the template. Their structure and physical properties were characterized by means of scanning electron mi- croscopy （ SEM）, X-ray diffraction （ XRD）, X-ray photoelectron spectroscopy （ XPS）, photoluminescence （PL） and UV-Vis spectroscopy. The results show that the prepared Feo o05/TiO2 was reticular. When the calcination tem- perature increases from 600 to 800 ~C, content of anatase TiO2 in reticular TiO2 and Feo 0os/TiO/prepared was de- creased and doped Fe3＋ can lead to the transition of anatase to rutile phase. Compared with Degussa P25, the PL intensity of reticular TiO2 and Fex/TiO2 revealed a significant decrease, indicating that they had a low recombina- tion rate of photo-induced electrons and holes. The absorbance wavelength of obtained reticular TiO2 and Fex/TiO2 was red shift and the band gap energy was decreased. The photo-catalytic degradation of malachite green experi- ments indicated that the photo-catalytic activity of the as-prepared reticular TiO2 and Fex/TiO2 was much higher than that of commercial Degussa P25. Further investigation revealed that reticular Fe000JTiO2 has an excellent long-term stability and can be repeated used.