Colloidal TiO2 Nanocrystals/MEH-PPV Nanocomposites: Photo(electro)chemical Study

An extensive optical and photoelectrochemical study of blended systems composed of organic-capped TiO2
nanocrystals with either a spherical or rodlike morphology and a conjugated polymer, MEH-PPV, is presented.
The absorption and emission properties of the heterojunctions have been characterized both in solution and
in thin films. The blended structures deposited onto conductive substrates have been employed as active
layers in photoelectrochemical systems. The investigation has been focused on the photoinduced charge transfer
and recombination processes at the interface between the two components, as a function of the nanocrystal
shape and surface coating, and of the film thickness. The presence of a large number of interfaces available
for charge transfer is believed to play a fundamental role in enhancing the photoelectrochemical performances
of the dispersed heterojunctions. The reported results suggest that such MEH-PPV/TiO2 heterojunctions may
be exploited as potential active layers in future photovoltaic and photoelectrochemical devices.