Emission-photoactivity cross-processing of mesoporous interfacial charge transfer in Eu³⁺ doped titania

Céline Marie Leroy (1) , Hongfeng Wang (1) , Alexandre Fargues (1) , Thierry Cardinal (1) , Veronique Jubera (1) , Mona Tréguer-Delapierre (1) , Cédric Boissière (2) , Clément Sanchez (2) , Bruno Viana (2) , Fabienne Pellé (2)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 Chaire Chimie des matériaux hybrides

Periodic mesoporous Eu³⁺ doped titania materials were obtained through the EISA (Evaporation Induced Self Assembly) process. Eu³⁺ ions, entrapped within the semi-crystalline walls of the highly porous framework, appear to be advantageous during the probing of surface photochemical reactions. Its emission intensity is very sensitive to the presence of physisorbed molecules, in gas or liquid phase, that reside within the pores. In particular, strong fluctuations in intensity of the ⁵D₀ → ⁷F₂ transition were observed under UV light exposure on the time scale of tens of seconds. The emission modulation dynamics show a strong correlation with the crystallinity of the titania matrix. Correlation of the emission with the photocatalytic activity of the semiconductor for photodegradation of an organic molecule is observed. A model is proposed to describe the involved mechanisms.

Mots clés: Europium; Photocalysis; Luminescence; Porous materials

Domaines: Matériaux

Céline Marie Leroy, Hongfeng Wang, Alexandre Fargues, Thierry Cardinal, Veronique Jubera, et al.. Emission-photoactivity cross-processing of mesoporous interfacial charge transfer in Eu³⁺ doped titania. Physical Chemistry Chemical Physics, 2011, 13 (25), pp.11878-11884. ⟨10.1039/C0CP02509G⟩. ⟨hal-00604755⟩