Search

In this study, a series of luminescent mesoporous hybrid organometallo-silica materials were successfully prepared via sol–gel coordination chemistry. The condensation of organometallic Ir(III) and Pt(II) complexes containing a 2-(diphenylphosphino)ethyltriethoxysilane (PPETS) ligand with the silica precursor (TEOS) yielded hybrid materials with homogeneous metal incorporation in the silica network and excellent luminescent and textural properties. All the reactions were carried out at room temperature and in the absence of a surfactant. Powders and transparent gels were prepared by adjusting the synthesis conditions and amounts of incorporated organometallic complex, yielding very stable emissive materials.

The one-pot co-condensation of tetrabutyl orthotitanate (TBOT) and the neutral Ru(II) N3 dye or the new cationic Ir(III) complex [Ir(ppy)2(3,3′-H2dcbpy)]PF6 have yielded novel hybrid in-situ titanias, which present an exceptional stability against leaching or photodegradation of the coordination dye. The main advantages of this strategy are: i) high dye incorporation level, ii) narrowing band gap and iii) high stability. These materials exhibit much higher photocatalytic activity, under both UV and visible light, not only than the dye-free titania but also than the related dye-sensitized titania prepared by post-synthetic grafting. This in-situ synthetic approach is a promising alternative route to prepare highly stable dye-sensitized materials with great applicability potential.

The reduction of the band gap of titania is critically important to fully utilize its photocatalytic properties. Two main strategies, i.e. doping and partial reduction of Ti(IV), are the main alternatives available to date. Herein, we report a new synthesis strategy based on one-pot co-condensation of in situ prepared polymetallic titanium-alkoxide complexes with titanium tetrabutoxide. Using this direct reaction, it is possible to introduce organic compounds in the anatase phase, causing site distortions in the crystalline structure of the network. By using this strategy, a yellow and a black titania have been produced, with the latter showing a remarkable photocatalytic activity under visible-light.