Studies On The Photocatalytic Hydrogen Evolution Of Ethanolamines And The Effect Of Inorganic Anions On Hydrogen Produced Of Glucose Over Pt/TiO₂

In this paper, firstly, we studied the photocatalytic hydrogen evolution and decomposition of the pollutants over Pt/TiO₂ in the presence of ethanolamines (ethanolamine, diethanolamine and triethanolamine). The pollutants enhance photocatalytic hydrogen generation activity notably with their quick degradation. The effects of irradiation time, the initial concentrations and pH-value were investigated. The rate of the hydrogen generation and that of the decomposition of the ethanolamines reach maximum at about pH 8-9. The effect of concentration of the three ethanolamines on the hydrogen generation rate follows Langmuir-Hinshelwood kinetic model. The photocatalytic oxidation of ethanolamines mainly produces CO₂, H₂O and NH₃. Formaldehyde and ethanolamine were detected as intermediate products. A possible reaction mechanism was discussed.Secondly, using glucose as electron dornors, we investigated the effects of five inorganic anions (SO₄^2-, Cl^-, NO₃^-, H₂PO₄^-, HCO₃^-, CO₃^2-) on photocatalytic hydrogen evolution over Pt/TiO₂. Our results indicate that H₂PO₄^- decreased the amount of produced H₂ notably; SO₄^2-, Cl^-, NO₃^- showed slight inhibitive influence; but HCO₃^-, CO₃^2- increased the quantity of hydrogen evolution remarkably and CO₃^2- is better. The different effects are discussed by electrochemistry, UV—vis, FT-IR techniques and the measure of value of COD.