【摘要】 以介孔二氧化硅SBA-15为载体,采用等体积浸渍法制备了Fe/SBA-15.通过X射线衍射(XRD)、N2吸附-脱附、扫描电镜(SEM)、透射电镜(TEM)和X射线光电子能谱(XPS)等技术对其进行了表征,并用于对水溶液中罗丹明B(Rh B)的芬顿氧化.表征结果表明了Fe/SBA-15维持了长程有序的介孔结构,孔径和比表面积都有所下降,并呈现棒状体的聚集态,平均直径为0.6μm.Fe以α-Fe2O3的形态同时存在于介孔孔道内外.在Fe/SBA-15和H2O2同时存在条件下Rh B的去除是吸附和催化氧化降解的协同作用所致,并且与Fe/SBA-15投加量密切相关,但与初始溶液p H几乎无关.当Fe/SBA-15投加量为0.15 gL-1,Rh B初始浓度为10.0 mgL-1,H2O2/Fe3+摩尔比为2000:1,初始溶液p H为5.4和反应温度为21°C时,Rh B去除率达到了93%.Fe/SBA-15的Langmiur单分子层饱和吸附量为99.11 mgg-1.此外,采用H2O2浸泡方式对使用过的Fe/SBA-15可进行再生,连续6次循环使用后仍可维持80%的Rh B去除率,且每次使用后Fe浸出浓度都在0.1 mgL-1(或者0.6%(质量分数))以下.基于淬灭实验、UV-Vis光谱和气相色谱-质谱(GC-MS)联用仪分析的结果,提出了Rh B的去除机理.非均相芬顿催化剂Fe/SBA-15可用于去除像Rh B这样的生物难降解有机物.更多还原

【Abstract】 An Fe-loaded mesoporous silica SBA-15, Fe/SBA-15, was prepared by incipient wetness impregnation, characterized by X-ray diffraction(XRD), N2adsorption-desorption, scanning electron microscopy(SEM), transmission electron microscopy(TEM), and X-ray photoelectron spectroscopy(XPS) techniques and used for heterogeneous Fenton oxidation of dye Rhodamine B(Rh B) in aqueous solution. The characterization showed that the Fe/SBA-15 retained a mesoporous structure with a long-range ordered arrangement, reduced pore diameter and surface area, and existed as agglomerates of rod-like crystallites with a mean diameter of0.6 μm. The Fe species occurred both inside and outside the support pores in the form of α-Fe2O3 crystallites.The removal of Rh B in the presence of Fe/SBA-15 and H2O2 was shown to be caused by the synergistic effects of adsorption and catalytic oxidative degradation, and was closely related to Fe/SBA-15 dosage. Removal was almost independent of initial solution p H, with approximately 93% achieved at an Fe/SBA-15 dosage of 0.15gL-1, initial Rh B concentration of 10.0 mgL-1, H2O2/Fe3+molar ratio of 2000:1; initial solution p H of 5.4 and 21 °C.The Langmuir monolayer adsorption capacity of the Fe/SBA-15 was 99.11 mgg-1. In addition, Fe/SBA-15 can be easily regenerated by soaking in H2O2 then reused for up to six runs, with Rh B removal greater than 80%and Fe leaching below 0.1 mgL-1(or 0.6%(mass fraction)) for each run. A removal mechanism for Rh B by Fe/SBA-15 and H2O2 was proposed based on the quenching tests, UV-Vis spectra, and gas chromatography-mass spectrometry(GC-MS) analysis. The heterogeneous Fenton catalyst Fe/SBA-15 can be applied to remove nonbiodegradable organics such as dye Rh B.更多还原