负载MIL-53(Fe)的改性聚丙烯腈纤维光催化剂的制备及其性能

针对MIL-53(Fe)粉末作为光催化剂的光响应范围窄、催化效率低和难回收利用等问题,以偕胺肟改性聚丙烯腈(PAN)纤维作为载体,通过表面原位合成法制备了负载不规则MIL-53(Fe)的纤维MIL-53(Fe)-PAN。借助扫描电子显微镜、X射线衍射仪、红外光谱仪和紫外-可见漫反射光谱仪对其表面形态、微观结构和光吸收性能进行表征,并对其在染料降解中的光催化性能进行了研究。结果表明:原位合成的MIL-53(Fe)能够均匀分布于改性PAN纤维表面,部分MIL-53(Fe)呈现出一定的结晶性能,且纤维配体的电荷转移(LMCT)效应将其光谱响应范围拓宽至800 nm;由于纤维配体和对苯二甲酸配体的协同作用,使得MIL-53(Fe)-PAN在染料降解中显示出极高的可见光催化活性,远优于MIL-53(Fe)粉末及其直接负载改性PAN纤维催化剂,为高效金属有机框架材料(MOFs)光催化剂的结构调控提供了新的思路。

Preparation and performance of modified polyacrylonitrile fibers photocatalyst with MIL-53(Fe)

MIL-53(Fe) powder suffers from limited photoabsorption, low catalytic efficiency and poor recycling ability in the application of photocatalysis. A highly efficient MIL-53(Fe) photocatalyst was constructed with irregular structure via an in-situ synthesis method using amidoximated polyacryloni-trile(PAN) fiber as the support. The surface morphology, microstructure and light absorption performance of the photocatalyst were characterized and analyzed by scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy and UV-Vis diffuse reflectance spectroscopy, and the photocatalytic performance was evaluated by the degradation of an organic dye. The results indicate that the in-situ synthesized MIL-53(Fe) are evenly distributed on the modified PAN fibrous support, and partial MIL-53(Fe) exhibit certain crystalline properties. Furthermore, the fibrous ligand greatly extends the spectral response of MIL-53(Fe) to 800 nm through ligand-to-metal charge transfer (LMCT) effect. Benefiting from the synergistic effect of fiber ligand and terephthalic acid ligand, the in-situ produced MIL-53(Fe) shows high photocatalytic activity for dye degradation under visible light irradiation, much superior to the MIL-53(Fe) powder and the fiber supported MIL-53(Fe) using a direct combination method. The findings provide a novel approach to design high-efficiency photocatalysts based on metal organic framework materials.