菱形片状铁锰催化剂活化过硫酸盐降解四环素

采用草酸蚀刻法制备由普鲁士蓝类似物衍生的菱形片状铁锰双金属催化剂，活化过一硫酸盐（PMS）降解四环素.通过热重分析仪（TGA）、X射线粉末衍射仪（XRD）、扫描电子显微镜（SEM）、傅里叶变换红外光谱仪（FTIR）对催化剂进行表征，表明合成的催化剂FeMn/OA-350具有菱形片状的特殊结构.铁锰双金属的协同作用与片状结构上的活性位点有效地提高了四环素的降解效率.在初始pH=7、催化剂投加量为0.6g/L、PMS浓度为2mmol/L的最优条件下，仅在30min内可使20mg/L的四环素去除率高达100%，反应过程符合二级动力学（R²>0.9），催化剂具有较宽的pH值适用范围.自由基猝灭实验表明该体系下存在羟基自由基、硫酸根自由基、单线态氧以及超氧自由基，单线态氧作为主要作用基团.X射线光电子能谱（XPS）反映了铁锰元素存在价态以及双金属间的协同作用，不同铁锰价态变化的循环过程促进催化剂的活化性能，同时根据猝灭实验和XPS、LC-MS初步分析降解机制.

Rhombic sheet iron-manganese catalyst-activating peroxymonosulfate for tetracycline degradation

The first-attempt study used iron-manganese bimetallic catalyst derived from the Prussian blue analogues, and etched by the oxalic acid for activating peroxymonosulfate (PMS) to degrade tetracycline. According to thermogravimetric analyzer (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), the synthesized catalyst FeMn/OA-350 owned a special rhombic shape. Apparently, combined synergy of iron and manganese and abundant active sites on the sheet structure significantly augmented the oxidation performance of tetracycline. When catalyst dosage and PMS concentration were of 0.6g/L, and 2mmol/L, the removal rate of 20mg/L tetracycline was as high as 100% within only 30 min at neutral pH. The reaction process seemed to follow the second-order kinetics (R²>0.9). The free radical quenching experiments showed that hydroxyl radical, sulfate radical, singlet oxygen and superoxide radical existed in this system and singlet oxygen was the main functional group. X-ray Photoelectron Spectroscopy (XPS) data clearly exhibited the valence states of iron and manganese elements and the synergistic interactions between Fe and Mn. It was suggested that changes of different iron and manganese valence directly promoted the activation performance of the catalyst. Meanwhile, based on the quenching experiment, XPS and LC-MS analyses, the degradation process and mechanism were first proposed.