双花簇状铁锰催化剂活化过一硫酸盐降解MB

Activating Peroxymonosulfate by Bi-flower-cluster Iron-Manganese Catalyst Derived from Metal-Organic Framework for Methylene Blue Degradation

该文以金属有机骨架MIL-Fe(100)为模板,经锰掺杂和高温煅烧得到双金属衍生物作为催化剂,高效活化过一硫酸盐(PMS)用于降解亚甲基蓝(MB)染料。采用扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)和X射线能谱分析(EDS)对Fe_(1)Mn_(2)-400材料的表面晶貌和化学结构进行了表征,证明该催化剂具有特殊的双花簇状形貌。探究得出在Fe/Mn摩尔比为1∶2,催化剂投加量为0.3 g/L,PMS浓度为2 mmol/L的最优条件下,MB的降解率可达92.19%,TOC去除率为50.71%,反应过程符合伪一级动力学(R^(2)>0.9)。通过淬灭实验证明了在Fe1Mn2-400/PMS体系中,SO_(4)^(·-)和·OH均是降解MB的主要活性物种,其中·OH占主导作用。X射线光电子能谱(XPS)反映出铁锰之间的协同作用促进了Fe(Ⅲ)/Fe(Ⅱ)的价态循环,从而提高了PMS的激活效率,实现了MB的高效降解。

Using MIL-Fe(100) as a template,bimetallic Fe-Mn derivatives obtained by manganese doping and high temperature calcination were used as catalysts to activate peroxymonosulfate for methylene blue (MB) degradation.The surface morphology and structure of Fe_(1)Mn_(2)-400 was characterized by scanning electron microscopy (SEM),X-ray diffraction(XRD),transmission electron microscopy,Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectrometer (EDS),which proved that the catalyst owned special bi-flower-cluster morphology.Under the optimum conditions of the Fe/Mn molar ratio of 1∶2,0.3 g/L catalyst dosage,2 mmol/L PMS concentration,the degradation efficiency of MB could reach 92.19%,and the degradation process followed pseudo-first-order kinetics (R^(2)>0.9).According to the quenching experiment results,SO_(4)^(·-)and·OH are the main active species to degrade MB,and·OH plays a dominant role in the Fe_(1)Mn_(2)-400/PMS system.X-ray photoelectron spectroscopy (XPS) revealed that the synergistic effect between iron and manganese promoted the valence cycle of Fe(Ⅲ)/Fe(Ⅱ),thus improving the activation efficiency of PMS and realizing the efficient degradation of MB.