铁-锌卟啉框架材料及其可见光催化降解罗丹明

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

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(Rh B)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Rh B的降解表现出显著的催化活性,可见光照射90min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Rh B的降解率可达95.9%,后者仅为67.6%。

A three-dimensional iron(Ⅲ)-zinc(Ⅱ)porphyrin framework,PCN-600(Zn)was constructed using 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin]-Zn(ZnTCPP)as ligand and Fe as nodes.The resulting material was characterized by PXRD,SEM and UV-Vis DRS and used for the degradation of rhodamine B(RhB)under visible light irradiation.The effect of H2O2 concentration on the photocatalytic performance of PCN-600(Zn)was investigated.The main reactive species during the photocatalytic reaction were determined by capture experiments.In addition,the photocatalytic performance between PCN-600(Zn)and zirconium(IV)-zinc(II)porphyrin framework,PCN-222(Zn)was compared.The results showed that PCN-600(Zn)exhibited obvious catalytic performance for the degradation of RhB in the presence of H2O2.The degradation rate of RhB reached 94.2%under visible light irradiation for 90 min.With the increase of H2O2 concentration,the catalytic activity of PCN-600(Zn)improved gradually.The efficiency of catalyst was the greatest when the amount of H2O2 was 4 mL.Experiments proved that during the catalytic process,holes(h^+)were the main reactive species,and·OH and·O2^-also had a certain contribution.More importantly,the photocatalytic performance of PCN-600(Zn)was significantly better than that of PCN-222(Zn),and under the identical experimental conditions,the degradation rate of the former for RhB was 95.9%,and that of the latter was only 67.6%.