Abstract: The photocatalytic generation of hydrogen from water using single and binary component pollutants as electron donors in aqueous Pt/TiO2 suspension has been investigated. The adsorption of these donors on TiO2 was also monitored by in situ attenuated total reflection infrared spectroscopy (ATR-IR). In the single component system (formaldehyde, formic acid and oxalic acid), the efficiencies of electron donors follow the order:H2C2O4 >HCOOH >HCHO. The order is consistent with the adsorption strength of the electron donors on TiO2 determined by ATR-IR, which suggests that the hydrogen evolution efficiency is dependent on the strength of surface interaction. In the binary mixture systems consisting of oxalic acid and formic acid, the overall kinetics of hydrogen evolution and decomposition of pollutants are dependent on their adsorption strengths on TiO2 and their concentration levels as well. The result can be explained by their competitive adsorption on TiO2. ATR-IR characterization confirmed illustratively the above explanation.

Key words: Photocatalysis, Production of hydrogen, Organic pollutants, Adsorption, 　In situ IR