改性FeCo_(2)O_(4)活化PMS降解水中2,4-二氯苯氧乙酸

Modified FeCo_(2)O_(4)to activate PMS to degrade 2,4-dichlorophenoxyacetic acid in water

以离子液体为氮源、磷源和氟源,采用一步水热法将N、P、F的3种元素掺杂到FeCo_(2)O_(4)中合成了NPF-FeCo_(2)O_(4)催化剂,用于活化过一硫酸氢钾(PMS)降解水中2,4-二氯苯氧乙酸(2,4-D).分别采用透射电子显微镜(TEM)、X射线光电子能谱(XPS)、傅立叶红外光谱(FTIR)、X射线衍射(XRD)对催化剂进行表征.实验结果表明,当催化剂投加量为0.1 g·L^(-1)、PMS浓度为1 mmol·L^(-1)时,反应30 min后2,4-D的去除率可达100%;初始pH值在3到9的范围内,体系对2,4-D的去除效果不受影响,水中低浓度的Cl^(−)、HCO_(3)^(-)和腐殖酸对反应有轻微的抑制.通过电子自旋共振波谱(EPR)测试结果显示,相较于FeCo_(2)O_(4)和NP-FeCo2O4催化剂,NPF-FeCo_(2)O_(4)/PMS体系能产生更多的∙OH、SO_(4)^(·-)和^(1)O_(2).淬灭试验结果显示SO_(4)^(·-)为2,4-D降解过程中的主要活性氧物种.

The N,P and F co-doped FeCo_(2)O_(4)(NPF-FeCo_(2)O_(4))catalyst was prepared via the one-step hydrothermal method using ionic liquid as nitrogen,phosphorus and fluorine sources.The catalyst was applied to activate potassium hydrogen persulfate(PMS)for the degradation of 2,4-dichlorophenoxyacetic acid(2,4-D)in water.Transmission electron microscope(TEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction analysis(XRD)were employed to characterize the catalyst.The results showed that the removal rate of 2,4-D reached 100%after reaction for 30 min with 0.1 g·L^(-1)of catalyst and 1 mmol·L^(-1)of PMS.The removal of 2,4-D was not affected within pH 3—9,and the reaction was slightly inhibited by low concentrations of Cl^(−),HCO_(3)^(−)and humic acid.Electron paramagnetic resonance(EPR)results exhibited that the NPF-FeCo_(2)O_(4)/PMS system produced more∙OH,SO_(4)⋅^(−)and ^(1)O_(2) than the FeCo_(2)O_(4)and NP-FeCo_(2)O_(4)counterparts,and the predomination of SO_(4)⋅^(−)was clarified by the quenching test during the 2,4-D degradation.