PHOTOELECTROCHEMICAL PROPERTIES OF DYE-SENSITIZED ZR-DOPED SRTIO3 ELECTRODES

Zr-doped SrTiO3 was used as a photoanode in a three-electrode electroc hemical cell. The three organic dyes Safranin, Fluorescein and Eriochr ome black T were used as sensitizers in the cell. The results showed t hat applying the dyes in photoelectrochemical solar (PECS) cells incre ased the solar efficiency to 2-3 times its value without dyes. The eff iciency reaches its maximum value when the dye concentration is suffic ient to cover the surface of the semiconductor electrode with a contin uous monolayer. Dye concentration higher than this value resulted in a decrease of the efficiency. Mott-Schottky plots gave a doping density of 1.34 x 10(16) cm(-3) for the sample and a space charge width of 1. 5-2.0 x 10(-6)cm (pH dependent). H-2 was produced at zero bias in the presence of Safranin dye at a light intensity of 25 mW/cm(2) with an e fficiency of about 39%. Both H-2 and O-2 were produced in the stiochio metric ratio. Cyclic voltammetry (c.v.) measurements showed two cathod ic current peaks revealing two reduction processes at the semiconducto r electrode. (C) 1997 International Association for Hydrogen Energy.