Photocatalytic hydrogen production by dye-sensitized Pt/SnO2 and Pt/SnO2/RuO2 in aqueous methyl viologen solution

Hydrogen photoproduction by a rarely studied, wide band gap semiconductor, SnO2, in powder form loaded with Pt and RuO2 and sensitized by Ru(bpy)(3)(2+) and organic dyes or with low band gap semiconductor, CdS, was investigated. Acriflavin, Eosin Blue, Rhodamine B, Rose Bengal and Fluorescein were used as photosensitizers in the presence of methyl viologen and with or without a sacrificial agent, EDTA. The effects of variation in concentrations of Ru(bpy)(3)(2+) and MV(2+) were studied. The maximum rate of hydrogen production was observed at [Ru(bpy)(3)(2+)] = 3.75 x 10(-5) mol dm(-3) and [MV(2+)] = 2.5 x 10(-5) mol dm(-3). The efficiency of the sensitizers in hydrogen production was found to decrease in the order: Eosin Blue > Rose Bengal > Ru(bpy)(3)(2+) > rhodamine B = acriflavin > fluorescein. Copyright (C) 1996 International Association for Hydrogen Energy