摘要
采用水热-煅烧两步法成功合成了具有高催化活性和稳定性的介孔铁锰纳米颗粒(FMNPs).通过扫描电子显微镜(SEM)、X 射线能谱仪(EDS)、比表面及孔径分析仪(BET)、傅里叶变换红外光谱仪(FTIR)、X射线粉末衍射仪(XRD)等表征分析了FMNPs的形貌和结构等理化性质.合成的催化剂具有丰富的介孔和较大的比表面积,有利于污染物的催化降解.为了评估催化剂的可重复使用性、稳定性和适应性,研究不同反应条件下活性黑5(RBK5)的降解效率.在初始pH值为7、过一硫酸盐(PMS)浓度为2mmol/L、催化剂用量为0.2g/L的最佳条件下,10mg/L RBK5在60min内的去除率可达96.74%.从反应机理来看,电子顺磁共振(EPR)、淬灭实验和计时电流(i-t)曲线显示非自由基途径(1O2、介导的电子转移)在降解体系中占据主导地位.X射线光电子能谱(XPS)分析表明,Fe和Mn的协同作用促进了Fe3+/Fe2+与Mn2+/Mn3+的氧化还原循环,加速了电子向PMS的转移,从而提高了FMNPs活化PMS的效率.
Abstract
Mesoporous FeMn nanoparticles(FMNPs)with high catalytic activity and stability were successfully synthesized by a two-step hydrothermal-calcination method.The physicochemical properties,morphology,and structure of FMNPs were analyzed by scanning electron microscopy(SEM),X-ray energy dispersive spectroscopy(EDS),Specific surface and pore size analyzer(BET),Fourier transform infrared spectroscopy(FTIR),and X-ray powder diffractometry(XRD).The synthesized catalysts,featuring abundant mesopores and a large specific surface area,significantly enhanced the catalytic degradation of organic pollutants.To assess the reusability,stability,and adaptability of the catalysts,degradation experiments were conducted with reactive black 5(RBK5)under various conditions.The optimal parameters were established at a pH of 7,a persulfate(PMS)concentration of 2mmol/L,and a catalyst dosage of 0.2g/L,achieving a 96.74%removal of 10mg/L RBK5 within 60 minutes.The catalytic mechanism was investigated through Electron Paramagnetic Resonance(EPR),quenching experiments,and Chronocurrent(i-t)tests,confirming that the non-radical pathway(1O2 and mediated electron transfer)played a dominant role in the degradation process.X-ray photoelectron spectroscopy(XPS)analysis revealed that the synergistic effect between Fe and Mn promoted the redox cycle of Fe3+/Fe2+and Mn2+/Mn3+,accelerating the electron transfer to PMS and thereby boosting the activation efficiency of PMS.
基金项目
厦门市建设局建设科技项目补助项目(XJK2023-1-10)
NETL
NSTL
万方数据