Photocatalytic hydrogen generation in the presence of ethanolamines over Pt/ZnIn2S4 under visible light irradiation

Using ethanolamine (EA), diethanolamine (di-EA) and triethanolamine (tri-EA) as electron donors, the photocatalytic hydrogen evolution and decomposition of the electron donors (pollutants) over Pt/ZnIn 2 S 4 have been investigated. The Pt was deposited on ZnIn 2 S 4 by in situ photoreduction. The three ethanolamines improve notably photocatalytic hydrogen generation with their simultaneous degradation, and their activity order for hydrogen evolution is tri-EA ≫ di-EA > EA. The adsorption of these donors on ZnIn 2 S 4 was monitored by in situ attenuated total reflection infrared spectroscopy (ATRIR). The order of their adsorption intensity is EA > di-EA ≫ tri-EA. The activity order depends on their molecular structure and adsorption performance. The effect of concentration of the pollutants on the hydrogen generation rate is consistent with a Langmuir–Hinshelwood kinetic model. The weak basic condition is favorable for the photocatalytic hydrogen generation. A possible reaction mechanism was discussed.