Photoreduction of CO2 over Ruthenium dye-sensitized TiO2-based catalysts under concentrated natural sunlight

Metal doped TiO2 catalyst sensitized with RuII(2,2′-bipyridyl-4,4′-dicarboxylate)2-(NCS)2 (N3 dye) is employed to photoreduce CO2 with H2O under concentrated natural sunlight to fuels in an optical-fiber photoreactor. Production rate of methane of 0.617 μmol/g-cat h is measured on N3-dye-Cu(0.5 wt%)-Fe(0.5 wt%)/TiO2 coated on optical fiber in April 12, 2007 in Taipei, Taiwan with the average concentrated solar light intensity of 20 mW/cm2. Full absorption of visible light of N3-dye along with efficient charge transfer in N3 dye–TiO2 system give rise to the superior photoreduction of the resulting dye adsorbed catalyst.