Flaig Sylvia, Akbarzadeh Johanna, Dolcet Paolo, Gross Silvia, Peterlik Herwig, Hüsing Nicola
Materials Chemistry, Paris-Lodron University Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg (Austria), Fax: (+43) 662-8044-622.
Chemistry. 2014 Dec 22;20(52):17409-19. doi: 10.1002/chem.201402873. Epub 2014 Nov 3.
Hierarchically organized silica-titania monoliths were synthesized under purely aqueous conditions by applying a new ethylene glycol-modified single-source precursor, such as 3-[3-{tris(2-hydroxyethoxy)silyl}propyl]acetylacetone coordinated to a titanium center. The influence of the silicon- and titanium-containing single-source precursor, the novel glycolated organofunctional silane, and the addition of tetrakis(2-hydroxyethyl)orthosilicate on the formation of the final porous network was investigated by SEM, TEM, nitrogen sorption, and SAXS/WAXS. In situ SAXS measurements were performed to obtain insight into the development of the mesoporous network during sol-gel transition. IR-ATR, UV/Vis, XPS, and XAFS measurements showed that up to a Si/Ti ratio of 35:1, well-dispersed titanium centers in a macro-/mesoporous SiO2 network with a specific surface area of up to 582 m(2) g(-1) were obtained. An increase in Ti content resulted in a decrease in specific surface area and a loss of the cellular character of the macroporous network. With a 1:1 Si/Ti ratio, silica-titania powders with circa 100 m(2) g(-1) and anatase domains within the SiO2 matrix were obtained.
通过应用一种新的乙二醇改性单源前驱体，如与钛中心配位的3-[3-{三(2-羟基乙氧基)硅烷基}丙基]乙酰丙酮，在纯水性条件下合成了分层组织的二氧化硅-二氧化钛整体材料。通过扫描电子显微镜（SEM）、透射电子显微镜（TEM）、氮吸附和小角X射线散射/广角X射线散射（SAXS/WAXS）研究了含硅和钛的单源前驱体、新型糖基化有机官能硅烷以及原硅酸四(2-羟乙基)酯的添加对最终多孔网络形成的影响。进行原位SAXS测量以深入了解溶胶-凝胶转变过程中中孔网络的发展。红外衰减全反射（IR-ATR）、紫外/可见（UV/Vis）、X射线光电子能谱（XPS）和X射线吸收精细结构（XAFS）测量表明，在Si/Ti比高达35:1时，在比表面积高达582 m² g⁻¹的大孔/中孔SiO₂网络中获得了分散良好的钛中心。Ti含量的增加导致比表面积降低以及大孔网络的蜂窝状特征丧失。在Si/Ti比为1:1时，获得了比表面积约为100 m² g⁻¹且在SiO₂基质内含有锐钛矿域的二氧化硅-二氧化钛粉末。
