铁-锌卟啉框架材料及其可见光催化降解罗丹明B

Iron(III)-Zinc (II) porphyrin Framework for Visible Light Photocatalytic Degradation of Rhodamine B

摘要:

以5,10,15,20-四-(4-羧基苯基)锌卟啉(ZnTCPP)为配体，以金属Fe为节点构筑了具有三维网状结构的铁-锌卟啉框架材料PCN-600(Zn)，采用PXRD、SEM、UV-vis DRS对所得材料进行了表征，并将其用于可见光下罗丹明B(RhB)的降解反应，考察了H2O2浓度对PCN-600(Zn)光催化性能的影响，并通过捕获实验确定了光催化反应过程中的主要活性物种，对比了PCN-600(Zn)与另一种锆-锌卟啉框架材料PCN-222(Zn)的光催化性能。结果表明，在H2O2的协同作用下，PCN-600(Zn)对RhB的降解表现出显著的催化活性，可见光照射90分钟后降解率可达94.2%，在实验范围内，随着H2O2浓度的增加，PCN-600(Zn)的催化活性不断提高，H2O2用量为4 mL时可最大程度上提升催化剂效率；实验证明在催化过程中，空穴（h+）为主要活性中间体，·OH 和·O2-也起到了一定的作用。此外，PCN-600(Zn)的光催化性能明显强于PCN-222(Zn)，相同实验条件下，前者罗丹明B的降解率可达95.9%，后者仅达67.6%。

Abstract:

A three-dimensional iron(III)-zinc (II) porphyrin framework PCN-600(Zn) was constructed, with the 5,10,15,20-tetrakis (4-carboxyphenyl) porphyrinato]-Zn (ZnTCPP) as the ligands, and the Fe as the nodes. The resulting material was characterized by powder X-ray diffraction, scanning electron microscopy, ultraviolet-visible diffuse reflectance spectra. After that, it was used for the degradation of rhodamine B (RhB) under visible light irradiation. And we studied the effect of H2O2 concentration on the degradation efficiency of PCN-600 (Zn) as well as the main reactive species during the photocatalytic reaction. In addition, we compared the photocatalytic performance of PCN-600 (Zn) and PCN-222 (Zn), a zirconium (IV)-zinc (II) porphyrin framework. The experiment results show that the catalytic performance of PCN-600(Zn) is not very obvious for the degradation of RhB. However, it exhibits a significant performance with the synergistic effect of H2O2. And in the experimental range, with the increase of H2O2 concentration, the catalytic performance of PCN-600 (Zn) gradually improves. Experiments prove that during the catalytic process, holes (h ) are the main reactive species, and ?OH and ?O2- also make a certain contribution. More importantly, the photocatalytic performance of PCN-600 (Zn) is significantly better than that of PCN-222 (Zn).