The synthesis and characterization of dinuclear ruthenium sensitizers and their applications in photocatalytic hydrogen production

A dinuclear ruthenium(II) dye sensitizer, ([Ru2(bpy)4BL](ClO4)2) referred as Compound 1, where bpy = 2,2′-bipyridine, BL = 2,2′-((1E,1′E)-(((E)-diazene-1,2-diyl-bis(2,1-phenylene))-bis(azanylylidene))-bis (methanylylidene)) diphenol (a bidentate bridging ligand), was designed, synthesized and characterized. The dye sensitizer was used on the photocatalytic water splitting for hydrogen (H2) production over TiO2 (P25) under visible light (λ ⩾ 400 nm) irradiation using triethanolamine (TEOA) as a sacrificial electron donor. The dye sensitized-TiO2 demonstrated a good stability and sufficient reproducibility for over 6 h. The photosensitization ability of the sensitizer was due to its conjugation system, large molecular area, TiO2 linkage mode and the antenna effect.

Graphical abstractThe synthesis of a dinuclear ruthenium(II) dye sensitizer was reported. The dye sensitizer was used on the photocatalytic water splitting for hydrogen (H2) production over TiO2 (P25) under visible light (λ ⩾ 400 nm) irradiation, and it demonstrated a good stability and sufficient reproducibility for over 6 h.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The synthesis and characterization of a dinuclear ruthenium complex. ► UV–vis titration spectra of the dinuclear complex were studied. ► Under visible light, the complex showed high effective hydrogen (H2) production. ► The “antenna effect” was used to explain the method of charge transfer.