PHOTOELECTROCHEMISTRY OF ZNO THIN-FILM ELECTRODE SENSITIZED BY AN OXOURANIUM (VI) COMPLEX IN AN ACETONITRILE PHOTOCELL

The photosensitizing ability of tetraethylammonium bis-(isomaleonitril o) dioxouranate(VI), (Et4N)2[UO2(i-MNT)2], studied at the n-ZnO/aceton itrile interface, is shown by the enhancement observed in photocurrent with (Et4N)2[UO2(i-MNT)2] in comparison to that obtained without the sensitizer. The flat-band potential is -0.40 V vs SSCE. (Et4N)2[UO2(i- MNT)2] acts as an acceptor-type sensitizer as concluded from the energ y-level diagram constructed using its redox potential coupled with its excitation energy and the flat-band potential of ZnO electrode. Long- term stability of the photocurrent under continuous illumination of th e electrode is also studied.