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Hierarchically Organized Silica–Titania Monoliths Prepared under Purely Aqueous Conditions
Author(s) -
Flaig Sylvia,
Akbarzadeh Johanna,
Dolcet Paolo,
Gross Silvia,
Peterlik Herwig,
Hüsing Nicola
Publication year - 2014
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201402873
Subject(s) - materials science , mesoporous material , anatase , small angle x ray scattering , acetylacetone , tetraethyl orthosilicate , chemical engineering , titanium , ethylene glycol , silane , aqueous solution , sorption , sol gel , inorganic chemistry , nanotechnology , organic chemistry , chemistry , adsorption , composite material , catalysis , photocatalysis , scattering , physics , engineering , optics , metallurgy
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 SiO 2 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 SiO 2 matrix were obtained.