光敏性多元核-壳微球絮凝剂的制备

Preparation of Photosensitive Multi Core-shell Microspheres Flocculant

摘要:

以Stöber法制备的单分散SiO2为核，采用溶胶-凝胶、界面沉积和表面活性剂模板法制备了多元核-壳结构微球SiO2@TiO2-Ag@SiO2，利用FT-IR、SEM、XRD、UV-Vis DRS、N2吸附-脱附、XPS对其结构和形貌进行了表征。结果显示：微球平均孔径、比表面积分别为2 nm、72.73 m2/g；受最外层SiO2影响，XRD未观察到锐钛矿相TiO2的特征衍射峰；紫外-可见漫反射光谱证实SiO2@TiO2-Ag@SiO2在365 nm处有吸收。在模拟太阳光照射下100 min，SiO2@TiO2-Ag@SiO2微球对亚甲基蓝(MB) 的光催化脱色率为97.6％；自然光下，对甲基橙溶液(MO)的絮凝沉淀时间为40 min，脱色率达99.7％。

Abstract:

The SiO2@TiO2-Ag@SiO2 core-shell microspheres were prepared with monodispersed SiO2(Stöber mothod) as core using sol-gel method, interface deposition method and surfactant template in turn. The structure and morphology of microspheres were investigated and analyzed by FT-IR, SEM, XRD, UV-vis, N2 adsorption desorption and XPS. The results show that average pore size and specific surface area of SiO2@TiO2-Ag@SiO2 microspheres is 2 nm, 72.73 m2/g, respectively. TiO2 diffraction peaks of anatase phase are not observed in XRD under the influence of the outer layer SiO2. UV-visible diffuse reflectance spectroscopy confirms that the core-shell microsphere is absorbed at 365 nm. Under simulated solar light source, the photocatalytic decolorization rate of methylene blue was 97.6% by SiO2@TiO2-Ag@SiO2. And the decolorization rate of methyl orange was 99.7% with 40 min flocculation precipitation under natural light.