Darmstadt 2008 – scientific programme

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MO: Fachverband Molekülphysik

MO 3: Femtosekundenspektroskopie I

MO 3.7: Talk

Monday, March 10, 2008, 15:45–16:00, 3G

Effect of Size Quantization on Interfacial Electron Transfer Dynamics in TiO2 Nanoparticles — •Hirendra N. Ghosh — Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-85, India — Max-Born Institute for Nonlinear and Short Pulse Spectroscopy, 12489, Berlin, Germany

Interfacial electron transfer dynamics was carried out in alizarin sensitized TiO2 nanoparticles with quantum size using femtosecond transient absorption (TA) spectroscopy. The TiO2 nanoparticles have been synthesized by arrested precipitation method. Electron injection dynamics were found to be multi-exponential with time constants of 100 fs, 17 ps and 50 ps. This observation was explained on the basis discreteness of the conduction band levels due to finite size effect. The back electron transfer (BET) dynamics found to be very slow as compared to the bulk system. The result gives us direct proof of non-adiabatic electron transfer reaction in a strong binding dye like alizarin.