SiO2@Fe2O3核-壳结构催化剂的制备及表征

采用优化的Stöber法制备了平均粒径为230 nm的单分散球形SiO₂颗粒,并以此为内核,通过水解沉积法制备了不同壳层厚度的核-壳结构SiO₂@Fe₂O₃催化剂。采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、N₂物理吸附和X射线衍射分析(XRD)等手段对催化剂进行表征,探讨了不同制备条件对SiO₂@Fe₂O₃催化剂形貌的影响。结果表明,通过水解沉积法制备的SiO₂@Fe₂O₃催化剂具有明显的核-壳结构,并且保持了原始SiO₂核的球形形貌,Fe₂O₃纳米粒子通过-OH的氢键作用连接在SiO₂表面,形成了2~10 nm厚的Fe₂O₃均匀连续包覆层。

Preparation and characterization of SiO2@Fe2O3 core-shell catalysts

The monodisperse SiO₂ microspheres with average diameter of 230 nm made by optimized Stöber method were used as core to prepare core-shell structure SiO₂@Fe₂O₃ catalysts with different shell thickness through hydrolysis precipitation. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), N₂ physical adsorption and X-ray diffraction (XRD) were used to characterize the size, structure and morphology of catalysts and the effects of different preparation condition on morphology were discussed. The characterization results indicate that SiO₂@Fe₂O₃ catalysts possess obvious core-shell structure and the spherical morphology of catalyst is kept. Iron oxide nanoparticles are attached to the silica surface through hydroxyl-bond and a 2~10 nm thick dense shell is formed.