Transparent thin films of mesoporous titania and mesoporous silica with embedded dye molecules as effective photocatalysts for pollutant mineralization and as optical gas sensors

• Applicant: Professor Dr. Michael Wark
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2002 to 2004
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5368516

The project is aiming at the preparation of transparent thin films of mesoporous titania and mesoporous silica with embedded titania clusters and/or dye molecules. The composites will be used as photocatalysts for waste water purification and optical gas sensors. The use of transparent thin films in photocatalytic reactions is favourable to suspensions of powders because light scattering is avoided and a number of films can be arranged in rows to achieve high efficiencies. Furthermore, the catalytically active films can be easily recovered. Ordered mesoporous structures of films will be created by self-assembled aggregates of pre-programmed organic molecules which ensure that the materials have very large accessible inner surface areas. Film manufacturing will be done by dip-coating and spin-coating. The activity of the pure films and of the functionalized films will be tested in suitable reactions, such as photodegradation of phenols or sodium sulfide in aqueous solutions. To enable an application of daylight also for the titania films, a sensibilization by dye molecules, e.g. phthalocyanines, covalently anchored on the inner surface of the films will be attempted. The properties of those materials regarding the optical sensing of different gases will be tested additionally.

• DFG Programme: Research Grants
• International Connection: Czech Republic
• Participating Persons: Dr. Jiri Rathousky; Professor Dr. Dieter Wöhrle