Surface Immobilization of Dinuclear Ruthenium Complexes Bearing Aqua Ligand on ITO or TiO2 Electrode: Fabrication and Its Photoelectrochemical Properties
|Shinya Masuno , Katsuhiko Kanaizuka , Masa-aki Haga|
Chuo university, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
Mimicking the natural photosynthetic system is one of the most important targets of supramolecular assemblies on surface to convert sunlight into stored chemical energy. With the idea of realizing photoelectrochemical energy conversion systems, the construction of photoelectrochemical oxidation catalytic system on surface has recently attracted significant attention. In this presentation, we present the syntheses and surface immobilization of novel dinuclear Ru complexes which consist of two separated functional moieties; i.e., one is photosensitizer and the other is oxidation catalyst. Ru-aqua complex as a catalytic site (Ru1) and a Ru-polypyridyl unit as a photosensitizer (Ru2) were bridged by bis(terpyridyl)benzene as shown in Fig 1, in which four phosphonate groups act as a anchor for the surface immobilization on ITO or TiO2 surface. Cyclic voltammogram of 1 on ITO electrode was shown in Fig.2. Two oxidation processes were observed at +0.75 V and +0.96 V vs Ag/AgCl. A surface coverage of 1 was 5.1 × 10-11 mol cm-2(=3.3 nm2molecule-1), which suggested that the complex was closely packed SAM of 1 on the ITO electrode. Photoelectrochemistry of 2 on ITO and TiO2 electrodes was measured in 0.1 M NaClO4 aqueous solution. Steady-state photo anodic current was observed for the complex 2 immobilized on TiO2 electrode. This preliminary result is promising for the development of new photoelectrochemical catalyst.
Presentation: Poster at SMCBS'2009 International Workshop, by Shinya Masuno
See On-line Journal of SMCBS'2009 International Workshop
Submitted: 2009-08-29 11:11 Revised: 2009-10-28 15:24