用偕胺肟改性聚丙烯腈(PAN)纤维与三氯化铁反应,在室温条件下制备了聚丙烯腈铁(Fe-PAN)配合物,并采用SEM,XRD和FT-IR等方法对其进行了表征.然后将其作为非均相光催化剂用于偶氮染料活性红MS的氧化降解反应,分别考察了催化剂用量、催化剂中铁离子含量(CFe-PAN)、pH值等因素对脱色率的影响,并应用紫外-可见光谱法对染料的氧化降解反应进行了分析.结果表明,改性PAN纤维中偕胺肟基团与铁离子发生了配位反应,增加PAN纤维中偕胺肟数或溶液中铁离子浓度能制备高铁离子含量的Fe-PAN催化剂.催化剂用量及铁离子含量增加都会促进活性红MS的降解反应.Fe-PAN催化剂在pH≤6.0的溶液中具有较高的催化活性,而在碱性介质中活性有所降低.在Fe-PAN催化剂存在下活性红MS的降解反应属于假一级动力学反应,催化剂用量和铁离子含量增加有利于提高活性红MS的降解反应速率常数.
A modified Fe-polyaerylonitrile fibrous photocatalyst (Fe-PAN) was prepared by a reaction between PAN fibers containing amidoxime group and ferric chloride at room temperature and characterized using SEM, XRD and FT-IR techniques, and then used as a heterogeneous catalyst for the photocatalytic degradation of Reactive Red MS in water. Some factors affecting the degradation of Reactive Red MS such as catalyst dosage, catalyst loading (CFe-PAN) and solution pH were investigated with respect to the decoloration rate. Additionally, the photocatalytic degradation of Reactive Red MS was examined by UV-Vis spectrometry. The results indicated that amidoxime groups from PAN fibers were able to ligate ferric ions in solution, and increasing amidoxime groups or ferric ion concentration led to the high CFe-PAN catalysts. Moreover, increasing catalyst dosage and CFe-PAN significantly accelerated the dye degradation. Fe-PAN catalyst showed high photocatalytic activity at pH≤6.0 solution, however, its activity was reduced insignificantly at alkaline medium. Photocatalytic degradation of Reactive Red MS in the presence of Fe-PAN catalyst followed the pseudo-first order kinetics, and increasing catalyst dosage and CFe-PAN also enhanced the degradation rate constant.