Laser-flash-photolysis-spectroscopy: a nondestructive method?
Jenny Schneider1, Konstantin Nikitin, Ralf Dillert
1Leibniz University Hannover, Institute for Technical Chemistry, 30167 Hannover, Germany. schneider@iftc.uni-hannover.de.
Faraday Discussions
|February 9, 2017
Summary
Intense laser illumination alters titanium dioxide (TiO2) nanoparticles, causing a color change and structural transformation. This is due to trapped electrons and oxygen release, impacting TiO2 properties.
Area of Science:
- Materials Science
- Photochemistry
- Nanotechnology
Background:
- Titanium dioxide (TiO2) is a widely used semiconductor material.
- Understanding its properties under laser illumination is crucial for applications.
Purpose of the Study:
- To investigate the effects of laser illumination during diffuse-reflectance laser-flash-photolysis on TiO2.
- To analyze the resulting changes in morphological and optical properties of TiO2 nanoparticles.
Main Methods:
- Diffuse-reflectance laser-flash-photolysis
- UV-vis spectroscopy
- Electron Paramagnetic Resonance (EPR) spectroscopy
Main Results:
- Laser illumination induced a grey-blue coloration in TiO2 nanoparticles.
- Formation of nonreactive trapped electrons and release of oxygen atoms were detected.
- A phase transition from anatase to rutile occurred in some TiO2 nanoparticles.
Conclusions:
- Laser illumination significantly alters TiO2's optical and morphological properties.
- Energy and charge transfer to the TiO2 lattice are responsible for structural changes.
- These findings offer insights into TiO2 behavior under photolytic conditions.
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