Abstract
Titanium dioxide nanocrystalline mesoporous thin films were prepared by Evaporation Induced Self Assembly process onto a FTO electrode and post-functionalized by ferrocenylphosphonic acid as grafted electrochemical probe. We showed that the pseudo-diffusive electron hopping between the redox species is related to the specific order of the TiO2 layer mesoporosity. The electrochemical measurements exhibit a very unusual behavior for a modified electrode as far as concern the slopes of the log I vs. log t curves, featuring a charge transfer occurring in a strongly anisotropic medium. The electronic diffusion coefficient values have been determined and fit well with results obtained for similar materials using soluble redox probes. This study demonstrates that efficient charge transfer can be driven when organic components are grafted to the mesoporous TiO2 semiconducting films