The Research Of Solvent Effect And Copper Based Catalyst For Dye Sensitized Photocatalytic Hydrogen Production System

In this thesis,the transfer of photoelectron on the dye sensitizer and photocatalyst in photocatalytic hudrogen production system were as the research pointcut.An excited-state Rose Bengal?RB^*?nonradiaton process was effectively suppressed by introducing DMSO into the RB-sensitized photocatalytic reaction,and the lifetime of the excited electrons was increased remarkably.Meanwhile,Cu/Cu₂O/Cu/TiO₂ catalyst was fabricated by in situ reduction from Cu₂O/TiO₂,and found that the interlayer metallic copper in Cu/Cu₂O/Cu/TiO₂ catalyst played an important role in the photocatalytic hydrogen evolution activitiy.The main content of this paper is as follows:1.Study on inhibiting the excited-state RB^*nonradiative process and enhancing photocatalytic hydrogen evolution efficiency by introducing DMSOThe nonradiative process of the excited-state RB^* was effectively suppressed by introducing a small amount of DMSO into RB-sentized photocatalytic hydrogen production systems,and the activity of photocatalytic hydrogen evolution was increased.Under visible light irradiation,the intermolecular proton transfer between the excited state RB^* and H₂O molecular made the excited state RB^* form the excited state anion RB^?*,and then was easily quenching in combination with H⁺,which leaded the loss of photoelectron of excited state RB^?* and made the hydrogen evolution activity decrease.The research found that a small amount of DMSO made the hydrogen bond between H₂O molecular and excited state RB* be weakened and the intermolecular proton transfer was inhibited.The measurement of hydrogen generation activity indicated that DMSO made the H₂ evolution of RB-sensitized Pt reached 1410.7 ?mol in120 min,and it was 4.48 times higher than that without DMSO.The highest apparent quantum efficiency?AQE?of 44.3% was reached at 550 nm.2.The role of interlayer metallic copper for visible photocatalytic hydrogen generation over Cu/Cu₂O/Cu/TiO₂ catalystThe Cu/Cu₂O/Cu/TiO₂ catalyst,containing the interlayer metallic copper,was fabricated by in situ photo-reduction.The research indicated that the interlayer metallic Cu had significant effect on hydrogen evolution activity.This interlayter metallic Cu provided a bridge for photoelectrons transfer from the conduction of TiO₂ to Cu₂O,making the life-time of electron transfer greatly prolonged.In addition,the ratio of interlayer metallic Cu and Cu₂O affected photocatalytic activity remarkably.The high transient photocurrent and long charge life-time?0.365 ns?were achieved over Cu/Cu₂O/Cu/TiO₂ catalyst when the mole ratio of the interlayer metallic Cu to Cu)₂O was 0.99.The activity of hydrogen production of Cu/Cu₂O/Cu/TiO₂ catalyst was three times than that of Cu/TiO₂ catalyst under same conditions,and Cu/Cu₂O/Cu/TiO₂ catalyst showed very good stability.