论文部分内容阅读
以光催化还原水制氢为指标反应系统地考察了若干种染料对TiO2的共敏化作用,研究表明曙红Y(EosinY,EY)和玫瑰红(Rose Bengal,RB)对TiO2的共敏化效果最为显著,而钌染料(Ru(bipy)3Cl2,Ru)分别与EY和RB的共敏化效果则不显著或没有共敏化效应.UV-Vis吸收光谱和荧光光谱技术对染料共敏化体系的表征结果表明,在EY/RB体系中显著的共敏化效应不仅与染料对可见光的吸收增加有关,而且还与染料分子之间的荧光共振能量转移(FRET)有关,这种荧光共振能量转移可有效降低染料激发态由于荧光猝灭导致的能量损失,提高光催化产氢效率.瞬态光电流实验和单色光产氢实验结果也进一步确证了这种作用.我们的研究结果还表明,在Ru/EY和Ru/RB体系中,必须加入甲基紫精作为电子中继试剂才能使催化剂具有光催化活性.在优化的反应条件下(λ≥420 nm),EY/RB共敏化体系的产氢量子效率分别比EY和RB单一染料敏化体系提高了36.3%和215.4%.
The co-sensitization of several dyes to TiO2 was systematically investigated with the photocatalytic reduction of hydrogen to hydrogen. The results showed that the sensitization of TiO2 to EosinY (EY) and Rose Bengal (RB) And the co-sensitization effect of Ru (bipy) 3Cl2, Ru) to EY and RB was not significant or no co-sensitization effect.UV-Vis absorption spectroscopy and fluorescence spectroscopy sensitized the dye The characterization results of the system show that the significant co-sensitization effect in EY / RB system is not only related to the increase of visible light absorption by dyes, but also to the fluorescence resonance energy transfer (FRET) between dye molecules. The fluorescence resonance energy The transfer can effectively reduce the energy loss due to fluorescence quenching and increase the efficiency of photocatalytic hydrogen production.The results of transient photocurrent experiment and monochromatic hydrogen production experiment further confirm this effect.Our results also show that , In the Ru / EY and Ru / RB system, methyl viologen must be added as an electron-relay reagent to make the catalyst photocatalytic activity.EY / RB co-sensitized under the optimal reaction conditions (λ≥420 nm) The system of hydrogen production quantum efficiency than the EY and RB A dye-sensitized system increased 36.3% and 215.4%.