DYNAMICS OF POLAR SOLVATION AT THE SURFACE OF A ZRO2 NANOPARTICLE

Polar solvation dynamics of a 95:5% (v/v) water/acetone mixture have b een measured at the ZrO2 nanoparticle surface by time-resolved fluores cence of a probe molecule adsorbed to the particle surface. The interf acial solvent response displays two sub-picosecond diffusive component s with the same time constants as bulk solution. However, the relative amplitudes for the individual relaxation components are significantly different, leading to a faster average solvation response for molecul es at the ZrO2 surface. Furthermore, the overall fluorescence Stokes s hift is approximately three times smaller for dye molecules adsorbed t o the nanoparticle surface. Implications for electron injection into s emiconductor nanoparticles are discussed. (C) 1998 Published by Elsevi er Science B.V. Ail rights reserved.