Investigation of surface modification of nanostructured TiO{sub 2} with EPR spectroscopy
- Argonne National Lab., IL (United States)
Surface complexation of colloidal titanium dioxide nanoparticles (40 {Angstrom}) by {alpha} substituted mercapto carboxylic acids results in the formation of charge transfer complex with an optical absorption threshold at 520 nm. It was found by EPR that illumination which leads to the charge transfer complex or band gap excitation results in the efficient spacial separation of photoinduced charges in surface modified TiO{sub 2}. Photogenerated holes are transferred to the derivatives at 4.2 K, while photogenerated electrons are trapped on TiO{sub 2} particle. However, visible excitation results in localization of photogenerated holes on the carboxyl group, while UV excitation leads to localization of photogenerated holes on the most distant hydrocarbon group of the derivative. The charge transfer complex and separation processes were examined by time resolved and pulsed EPR spectroscopies.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 370831
- Report Number(s):
- CONF-960376--
- Country of Publication:
- United States
- Language:
- English
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