TiO2 and Ag@TiO2 Nanostructures for Photo- and Electrocatalysis. The benefit of enhanced electric fields

• Applicant: Professorin Dr. Inez Weidinger
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 273679363

In this project TiO2 nanostructures are developed that exhibit strong enhanced electromagnetic fields at the TiO2 surface upon light illumination. These enhanced electric fields shall be used on the one hand to analyse surface bound molecules via surface enhanced Raman spectroscopy. On the other hand the influence of the locally enhanced light intensity, quantified by SERS, on the photocatalytic efficiency of TiO2 will be investigated. Different strategies are exploited to optimize field enhancement: In the first approach the local field intensity on the surface of pure nanostructured TiO2 will be modulated by varying its surface morphology . In the second approach amplification of local fields is achieved by addition of plasmonic silver. These silver nanostructures are passivated by an inert coating and are placed either below or above the TiO2 surface. As a test for photocatalytic activity the light induced degradation of Bisphenol and Rhodamine B, attached to TiO2, is investigated. If possible, we aim to detect degradation intermediates via SER spectroscopy. Furthermore the systems are tested for electrocatalytic applications using enzymes and molecular catalysts for O2 and H2O2 reduction. Due to the enhanced electric fields at the catalyst/TiO2 interface identification of reaction intermediates via SER spectro-electrochemistry shall be obtained.

• DFG Programme: Research Grants