Synthesis, Characterization And Visible Light Driven H₂Production In Molecular Systems Comprising Pt/TiO₂of Pyridine-containing Photosensitive Complexes

In this paper, pyridine-containing Ruthenium complexes were used as photosensitive dye. Platinize TiO2and different kinds of sacrifices composed of three component system to achieve visible light water splitting,the hydrogen evolution activity of the photocatalyst was investigated under visible light irradiation in aqueous acetonitrile solution. The main results are as follows:Ruthenium trichloride and1,10-Phenanthroline as raw material was exploited to synthesized four novel pyridine-containing Ruthenium complexes [Ru (L) bpy2(L1=2-phenyl-1H-1-imidazo [4,5-f][1,10] phenanthroline, L2=4-(1H-imidazo [4,5-f][1,10] phenanthroline acid, L3=4-(2-(phenyl)-1H-imidazo [4,5-f][1,10] phenanthroline-phenol, L4=4-(2-(phenyl)-1H-imidazo [4,5-f][1,10] phenanthroline benzoic acid. The prepared pyridine-containing Ruthenium complexes were characterized with IR,1HNMR, MS etc.It is found that they have a wide absorption range in the area of visible light by the measure of UV-visible spectroscopy. The cyclic voltammogram test proves the dye sensitizers match with the requirments of the energy gap of TiO2.A photocatalytic hydrogen evolution system was established with the Pt/TiO2as photocatalyst and300W xenon lamp as the simulated light source(using a420nm filter), and the concentration of the dye and species of electron donor (triethanolamine (TEOA), triethylamine (Et3N), Ascorbic acid) to the photocatalyst evolution activity was systematically studied. We put emphasis on the influence of initial pH,the solvent of acetonitrile and water as well as the the addition amount of Et3N system to the photocatalytic hydrogen evolution activity. It is revealed that the rate of hydrogen evolution can be significantly affected by the concentration of TEOA and Et3N as well as the initial pH. with the initial pH increases, the rate of hydrogen evolution in Et3N.showing a decreasing trend after the first increases while a linear decrease in Et3N. The optimal conditions were obtained:50mg Pt/TiO2as photosensitive catalyst,1.5×10-4mol/L photosensitive dye was added,15%(v:v) triethylamine as electron donor, and pH was adjust to10, the ratio of acetonitrile and water=1:1(v:v) to get the maximum amount of hydrogen production. On this basis, by liquid chromatography, We have researched the stability of dyes.