For different fields of applications, e.g. in sensing, catalysis, etc., doping of mesostructured silica films with metal oxides is of high importance for the compensation of the rather inert character of pure silica. In this approach, the focus lies on the preparation of titania-doped silica films, which can be used for photocatalysis or for catalyzing epoxidation reactions depending on the incorporated amount of titania. There are several routes for the preparation of catalytically active mesoporous silica films, e.g. post-treatment to incorporate active species after the porous silica-matrix was prepared. However, problems such as pore-blocking and an inhomogeneous distribution of the metal constitutes a big problem. Another possible way is the direct synthesis by mixing an alkoxysilane e.g. tetraethyl-orthosilicate (TEOS) with the titanium-analogue tetraethyl-orthotitanate (TEOT), which although won´t work in this case since hydrolysis and condensation rates of the silica and titania sources differ strongly and titania would precipitate in the sol.

For the preparation of mesostructured silica-titania films with a variable Si/Ti-ratio, the complexation of the titanium alkoxide precursor to the structure-directing agent, e.g. Brij56 has been reported previously. In this approach, the Ti-content is directly connected to the amount of surfactant and cannot be varied to a large extent. In this work, a novel more flexible approach is described based on the application of a preformed single-source precursor (SSP). This precursor was prepared from 3-acetyl-6-triethoxysilylhexane-2-one coordinated to titanium tetraisopropoxide. Applying this SSP in an evaporation-induced self-assembly process allows to deliberately tune the composition of the final film up to a Si : Ti ratio of 1. All materials are characterized by TEM, SAXS, XRD and nitrogen sorption. The potential and disadvantages of this approach are discussed in detail.

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