Photocatalytic performance of Ru doped anatase mounted on silica for reduction of carbon dioxide

• Published in: Applied catalysis. B, Environmental Vol. 62; no. 1-2; pp. 169 - 180
• Main Authors: Sasirekha, Natarajan, Basha, Sheikh John Sardhar, Shanthi, Kannan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 10.01.2006; Elsevier
• Subjects: Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Hole scavenger; Photocatalytic reduction; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Reduction of CO2 with H2O; Ru/TiO2; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; TiO2/SiO2; Ru/TiO2; Reduction of CO2 with H2O; TiO2/SiO2; Photocatalytic reduction; Hole scavenger; Ruthenium; Anatase; Photocatalysis; Carbon dioxide; Transition element compounds; Transition metal; Silica; Supported catalyst; Chemical reduction; Titanium oxide; Platinoid
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2005.07.009

Ru doped anatase supported on silica was prepared by solid-state dispersion method and examined for the photocatalytic reduction of carbon dioxide in aqueous medium at ambient conditions. To assist in interpreting the photocatalytic behaviour of Ru-TiO2/SiO2, reference systems consisting of Ru doped TiO2 and TiO2 supported on SiO2 were also analyzed and the conditions were optimized. Ru/TiO2 photocatalysts with metal loadings of 0.1, 0.3, 0.5 and 1.0wt% were prepared by impregnation method and a series of TiO2/SiO2 catalysts with low TiO2 (1, 3, 5 and 10wt%) contents were prepared by solid-state dispersion method. The photocatalysts were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), UV–vis DRS, FT-IR and Raman spectroscopy. The results showed that TiO2 particles with Ru ions have higher photocatalytic activity than undoped TiO2 and the optimum Ru loading was found to be 0.5wt%. Nevertheless, the yield increased notably when TiO2 was supported on SiO2. This strong enhancement suggests that in 10wt% TiO2/SiO2 the efficiency of charge separation is strongly influenced through the presence of TiOSi bridging bonds. On the contrary, Ru-TiO2/SiO2 has no significant improvement in activity over TiO2/SiO2 except that it shows nearly quadruple times higher activity for the formation of methanol than Ru/TiO2. The difference in the photocatalytic activity is related to its physico-chemical properties.