Using glucose and sucrose as the electron donors,the photocatalytic hydrogen evolution over Pt/TiO2 was investigated.Glucose and sucrose enhance notably the activity for hydrogen generation.The amounts of produced H2 increase almost proportionally to time within 5 h irradiation in the reaction systems of the two electron donors.The effect of the initial concentration of glucose and sucrose on the reaction rate is consistent with the Langmuir-Hinshelwood kinetic model.After 5 h irradiation,the COD（chemical oxygen demand） in the reaction system of glucose and in that of sucrose decrease by 33.2%,11.4% respectively.The effect of electron donors on the flat-band potential of conduction band of TiO2 electrode was investigated.The flat-band potential of conduction band of TiO2 electrode in the presence of the electron donors shifts negatively,and the shift in the presence of glucose is larger than that in the presence of sucrose due to glucose having a larger adsorption amount on TiO2.
