Synthesis of mesoporous Fe-SiO2 composites and adsorption and synergetic catalytic performance
-
摘要: 采用原位一步合成法,在含有模板剂、AlCl3和H2O的弱酸性反应体系中,引入Si源和Fe源,通过原位共沉积的方式,成功制备出Fe修饰的介孔SiO2(Fe-SiO2)复合材料。采用XRD、N2吸附、FTIR、UV-vis、SEM和EDS等手段表征了介孔Fe-SiO2复合材料样品的结构、形貌和化学组成;将所获得的介孔Fe-SiO2复合材料用于吸附和协同催化去除水体中有机污染物亚甲基蓝(MB);考察了Fe源添加量对介孔Fe-SiO2复合材料结构和性能的影响。研究结果表明:合成体系中rFe:Si ≤ 0.05(摩尔比)时,所得Fe-SiO2介孔材料保留了介孔孔道的高度有序性和大比表面积(860~889 m2·g-1),Fe在介孔Fe-SiO2复合材料中主要以四配位骨架掺杂的形式存在;当rFe:Si=0.1时,其比表面积下降为526 m2·g-1,Fe以骨架内和骨架外氧化物的形式共存于介孔Fe-SiO2复合材料中。所有介孔Fe-SiO2复合材料在去除MB的实验中均表现出很大的吸附容量和优良的多相类芬顿催化能力。其中,rFe:Si=0.05时所获得的介孔Fe-SiO2复合材料样品性能最佳,对高浓度MB(250 mg·L-1)的吸附和催化总量达到213 mgg-1。Abstract: A series Fe-modified mesoporous SiO2 (Fe-SiO2) composites were successfully synthesized via one-step method. Fe species can be co-precipitated with the siliceous species in the mildly acidic aqueous solutions that contain the template and aluminum chloride. The structure, morphology and chemical composition of Fe-SiO2 composites were characterized by XRD, N2 physisorption, FTIR, UV-vis, SEM and EDS techniques. The obtained mesoporous Fe-SiO2 composites was then used to adsorb and synergetic catalytic degrade organic methylene blue (MB) from wastewater. The effects of the initial Fe content in the reaction solution on the structure and property of Fe-SiO2 composites were thoroughly investigated. The results show that the mesoporous Fe-SiO2 synthesized with relatively low Fe content (rFe:Si ≤ 0.05) has a well-ordered mesostructure and large surface area (860-889 m2·g-1), and Fe species are highly dispersed in the framework of the SiO2. At high Fe content (rFe:Si=0.1), the obtained mesoporous Fe-SiO2 has a reduced surface areas of 526 m2·g-1, and Fe species are existing in the matrix of SiO2 as the both framework and extra-framework forms. All of the mesoporous Fe-SiO2 composites show high adsorption capacities and the superior heterogeneous Fenton-like catalytic activities for the removal of MB from aqueous solutions. Among them, the Fe-SiO2 sample synthesized with the rFe:Si of 0.05 presents the best performance. It can remove 213 mgg-1 of high concentrated MB (250 mg·L-1) by adsorption and synergetic catalytic degradation.
-
Key words:
- mildly acidic media /
- mesoporous Fe-SiO2 /
- adsorption /
- Fenton-like catalysis /
- methylene blue
点击查看大图
计量
- 文章访问数: 673
- PDF下载量: 239
- 被引次数: 0