改性MIL-101(Fe)非均相芬顿反应降解罗丹明B

Degradation of rhodamine B by modified MIL-101(Fe)heterogeneous Fenton reaction

金属有机骨架材料MIL-101(Fe)具有一定的催化活性,为进一步提升其催化性能,利用金属掺杂和柠檬酸调节对其进行改性,制备得到Cu/Ce-MIL-101(Fe)和Cu/Ce-MIL-101(Fe)-N两种改性材料。通过X射线衍射(XRD)、傅立叶变换红外光谱(FT-IR)、场发射扫描电镜(SEM)、氮气吸附脱附测试及X射线光电子能谱(XPS)对材料进行表征。结果显示,改性后催化剂具有相似的骨架结构和化学键组成,活性位点的结合能减少0.2~0.3 eV。金属掺杂和柠檬酸调节改性后Cu/Ce-MIL-101(Fe)-N平均孔径增大至14.932 nm。采用非均相芬顿反应研究降解时间和pH对罗丹明B降解性能的影响,结果表明,在温度为25℃,罗丹明B初始质量浓度为24 mg/L,溶液pH为4且Cu/Ce-MIL-101(Fe)-N投加量为0.2 g/L,3%(体积分数)H_(2)O_(2)投加量为60 mL/L,反应60 min时,罗丹明B降解率高达98%。改性前后催化剂降解过程均更符合准一级动力学模型。其中,Cu/Ce-MIL-101(Fe)-N能够在60 min内达到降解平衡,降解效率更高。

Metal-organic framework material MIL-101(Fe)has certain catalytic activity.In order to further improve its catalytic performance,Cu/Ce-MIL-101(Fe)and Cu/Ce-MIL-101(Fe)-N modified materials were prepared by metal doping and citric acid regulation.The materials were characterized by XRD,FT-IR,SEM,nitrogen adsorption and desorption test and XPS.The results showed that the modified catalysts had similar skeleton structure and chemical bond composition,and the binding energy of active sites was reduced by 0.2 to 0.3 eV,and the average pore size of Cu/Ce-MIL-101(Fe)-N increased to 14.932 nm after metal doping and citric acid modification.The effects of degradation time and pH on the degradation performance of rhodamine B were investigated by heterogeneous Fenton reaction.The results showed that when the reaction temperature was 25℃,the initial concentration of rhodamine B was 24 mg/L,the pH was 4,and the Cu/Ce-MIL-101(Fe)-N dosage was 0.2 g/L,3%(volume fraction)H_(2)O_(2)dosage was 60 mL/L,the degradation rate of rhodamine B reached 98%after 60 minutes reaction.The degradation process of catalysts before and after modification conformed to quasi-first-order kinetic model.Among them,Cu/Ce-MIL-101(Fe)-N had higher degradation efficiency,which could reach degradation equilibrium within 60 minutes.