State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, P. R. China.
Chemistry. 2013 Jul 15;19(29):9592-8. doi: 10.1002/chem.201300438. Epub 2013 Jun 13.
Mesoporous ferrihydrite/SiO2 composites were synthesized according to a water-in-oil microemulsion method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetry, nitrogen-adsorption/desorption, and by X-ray photoelectron spectroscopy. The as-prepared porous ferrihydrite/SiO2 composites showed an excellent adsorption performance for formaldehyde (HCHO) removal from indoor air at ambient temperature. It was found that the aging time during the synthesis had a significant impact on the pore structure, surface area, and HCHO adsorption of these materials. The ferrihydrite/SiO2 composite that was aged for 3 h in the presence of tetraethyl orthosilicate (TEOS) exhibited a relatively high HCHO adsorption capacity, as well as good recyclability, which was attributed to a relatively large BET surface area, optimal pore size, a suitable Si/Fe atomic ratio, and a synergistic effect between ferrihydrite and SiO2. This work not only demonstrates that porous ferrihydrite/SiO2 composites can act as an efficient adsorbent toward HCHO, but suggests a new route for the rational design of cost-effective and environmentally benign adsorbents with high performance for indoor air purification.
介孔水铁矿/SiO2 复合材料是通过水包油微乳液法合成的，并通过 X 射线衍射、扫描电子显微镜、透射电子显微镜、傅里叶变换红外光谱、热重分析、氮气吸附/脱附以及 X 射线光电子能谱进行了表征。所制备的多孔水铁矿/SiO2 复合材料在室温下对室内空气中的甲醛（HCHO）具有优异的去除性能。研究发现，合成过程中的老化时间对这些材料的孔结构、比表面积和 HCHO 吸附性能有显著影响。在正硅酸乙酯（TEOS）存在下老化 3 h 的水铁矿/SiO2 复合材料表现出较高的 HCHO 吸附容量和良好的可循环性，这归因于较大的 BET 比表面积、最佳的孔径、合适的 Si/Fe 原子比以及水铁矿和 SiO2 之间的协同效应。这项工作不仅证明了多孔水铁矿/SiO2 复合材料可以作为 HCHO 的有效吸附剂，还为设计具有高效、经济和环保性能的用于室内空气净化的新型吸附剂提供了新途径。
