钛铁矿制备二氧化钛-四氧化三铁复合材料及其光催化应用

TiO_2因具有多种优异的特性被广泛应用在半导体光催化领域,但是纳米结构的TiO_2颗粒细微,在进行光催化反应之后,难以回收再利用。本文以廉价钛铁矿为原料制备光催化剂TiO_2,同时利用副产物铁合成Fe_3O_4,并采用简单温和的浸渍法制备Fe_3O_4/TiO_2磁性复合材料。通过XRD、FT-IR、SEM、EDS等手段对材料形态结构进行表征分析,并以光降解有机污染物若丹明B为探针反应,考察其光催化性能。结果表明,质量比为1∶10的Fe_3O_4/TiO_2复合材料结构稳定、分散均匀,具有最优的光催化活性(波长356nm下反应3h,若丹明B降解率达到64.0%),并表现出良好的重复性。同时,动力学结果显示降解符合一级反应动力学。

Preparation of Fe3O4/TiO2 composite from ilmenite and its photocatalytic performance

TiO₂ is widely used in semiconductor photocatalysis due to its excellent features. However, TiO₂ particles with nanoscale size is difficult to separate and recycle after the photocatalytic reactions. In this paper, we successfully synthesized the magnetic Fe₃O₄/TiO₂composite by the simple and mild dip-molding. Both the TiO₂ and Fe₃O₄ are originated by the cheap ilmenite as raw material. A series of characterization means including X-ray Diffraction(XRD), Fourier transform infrared spectrum(FT-IR), scanning electron microscope(SEM) and Energy Dispersion Spectrum(EDS) were used to analyze the surface structure of the Fe₃O₄/TiO₂composite. Furthermore, the performance of Fe₃O₄/TiO₂composite was investigated by using of photocatalytic degradation of Rhodamine B(Rh B) as a probe reaction. The results demonstrated that the ratio(weight, wt) 1:10 of Fe₃O₄/TiO₂composite exhibited stable structure and well dispersion, possessed the highest catalytic activity: the degradation rate of Rh B reached 64.0% after 3h under UV visible light(356 nm), and outstanding repeatability. The photocatalytic degradation reaction coincides with the first-order reaction kinetics.