Expanding the atrane route: Generalized surfactant-free synthesis of mesoporous nanoparticulated xerogels

A diversity of silica-based and non-silica nanoparticulated mesoporous xerogels have been synthesized from aqueous solution using a surfactant-free strategy, and starting from molecular atrane complexes as precursors. This approach constitutes an extension of the “atrane route” previously described for the surfactant-assisted synthesis of mesoporous materials, and allows us to unify the multiplicity of protocols described for the preparation of conventional xerogels. In fact, we have used exactly the same preparative conditions for obtaining all the compositions reported here. The xerogels synthesized in this way include pure silica (UVM-11), aluminosilicates and titanosilicates (M-UVM-11, M = Al, Ti), hybrid organic–inorganic silica-based derivatives, and also non-silica materials such as pure titania and alumina. Moreover, post-hydrothermal treatments allow modulating the mesopore average size in the ca. 3–30 nm range. The key factor making available such a diversity of materials is the inertness of the atrane complexes, which allows orchestrating the hydrolytic reactivity of different oxide-forming elements. In turn, this avoids subsequent phase segregation and results in chemically homogeneous materials.

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