铋掺杂介孔二氧化钛的制备及光催化动力学

以介孔分子筛(KIT-6)为载体,采用溶液浸渍法合成了铋(Bi)掺杂的介孔二氧化钛(TiO₂)光催化剂。利用XRD、TEM、SEM、XPS、N₂吸附-脱附法和拉曼光谱法等技术手段对材料的结构和形貌进行表征。通过紫外-可见吸收光谱法考察了催化剂对罗丹明B光催化降解效率,进一步考察了Bi的掺杂量对光催化反应速率的影响,并对光催化降解动力学进行了初步研究。结果表明,Bi掺杂的介孔TiO₂具有较窄的孔径分布(3~4 nm),而且吸收范围扩展到可见光区,其光催化活性明显高于商品TiO₂(P25)。随之Bi掺杂量的提高,反应速率常数也增大,其光催化降解罗丹明B的反应均符合准一级动力学方程。

Preparation and Photocatalytic Kinetic of Bismuth Doped Mesoporous Titanium Dioxide

A Bi doped mesoporous TiO₂ photocatalyst was prepared by solution impregnation method with mesoporous KIT-6 sieve as the carrier. The crystal structure and morphology of the photocatalyst was characterized with XRD, TEM, SEM, XPS, Raman spectrometer and physical adsorption instrument. Photocatalytic activity of the photocatalyst was investigated through degradation of Rhodamine B by UV-visible absorption spectrometry. The amount of doped Bi for impact on photocatalytic reaction rate and the kinetics of the photocatalytic degradation were studied. The results show that the Bi doped mesoporous TiO₂ have a narrow pore size distribution(3~4 nm), and the light absorption band of photocatalyst is extended to visible light area. Therefore, the photocatalytic activity of Bi doped mesoporous TiO₂ is significantly higher than that of commercial TiO₂(P25). The photocatalytic degradation reaction of Rhodamine B is corresponding to an equation of first order reaction. The photocatalytic reaction rate constant increases with increasing amount of the doping Bi.