Li Xiaodong, Sun Guanqing, Li Yecheng, Yu Jimmy C, Wu Jie, Ma Guang-Hui, Ngai To
Department of Chemistry, The Chinese University of Hong Kong , Shatin N.T., Hong Kong.
Langmuir. 2014 Mar 18;30(10):2676-83. doi: 10.1021/la404930h. Epub 2014 Mar 6.
We report a facile method for preparing porous structured TiO2 materials by templating from Pickering high-internal phase emulsions (HIPEs). A Pickering HIPE with an internal phase of up to 80 vol %, stabilized by poly(N-isopropylacrylamide)-based microgels and TiO2 solid nanoparticles, was first formulated and employed as a template to prepare the porous TiO2 materials with an interconnected structure. The resultant materials were characterized by scanning electron microscopy, X-ray diffraction, and mercury intrusion. Our results showed that the parent emulsion droplets promoted the formation of macropores and interconnecting throats with sizes of 50 and ~10 μm, respectively, while the interfacially adsorbed microgel stabilizers drove the formation of smaller pores (100 nm) throughout the macroporous walls after drying and sintering. The interconnected structured network with the bimodal pores could be well preserved after calcinations at 800 °C. In addition, the photocatalytic activity of the fabricated TiO2 was evaluated by measuring the photodegradation of Rhodamine B in water. Our results revealed that the fabricated TiO2 materials are good photocatalysts, showing enhanced activity and stability in photodegrading organic molecules.
我们报道了一种通过皮克林高内相乳液（HIPE）模板法制备多孔结构TiO₂材料的简便方法。首先制备了一种由聚（N-异丙基丙烯酰胺）基微凝胶和TiO₂固体纳米颗粒稳定的内相高达80体积%的皮克林HIPE，并将其用作模板来制备具有相互连接结构的多孔TiO₂材料。通过扫描电子显微镜、X射线衍射和压汞法对所得材料进行了表征。我们的结果表明，母体乳液滴分别促进了尺寸约为50和10μm的大孔和连通孔道的形成，而界面吸附的微凝胶稳定剂在干燥和烧结后促使在整个大孔壁中形成较小的孔（100nm）。在800℃煅烧后，具有双峰孔的相互连接结构网络能够得到很好的保留。此外，通过测量罗丹明B在水中的光降解来评估所制备TiO₂的光催化活性。我们的结果表明，所制备的TiO₂材料是良好的光催化剂，在光降解有机分子方面表现出增强的活性和稳定性。
