Dye sensitized artificial photosynthesis in the gas phase over thin and thick TiO2 films under UV and visible light irradiation

Ozcan, O.
Yukruk, F.
Akkaya, E. U.
Üner, Deniz
Perylene diimide based organic sensitizers capable of electron generation under illumination were used to initiate gas phase photo reduction reactions on TiO2 thin and thick film surfaces. For comparison [Ru(Bpy)(3)](2+) dye sensitizers were also studied. The photo reduction Of CO2 was carried out under static conditions in the gas phase. TiO2 films were coated on hollow glass beads via a sol-gel procedure. Pt was incorporated on the films either by adding the precursor salt in the sol, Pt(in), or by wet impregnation of calcined film with an aqueous solution of the precursor salt, Pt(on). Organic sensitizers were incorporated on the films by wet impregnation of the film from an aqueous solution. Under UV illumination, the methane yields of platinized TiO2 thin films decreased in the following order: Pt(on).TiO2 > Pt(in).TiO2 > TiO2. The presence of organic sensitizers inhibited the catalytic activity of pure and platinized TiO2 thick films under UV illumination. The relative enhancement of the reaction yields in the presence of the organic sensitizer under visible light illumination depended on the presence of Pt as well as the incorporation method of Pt in the TiO2 structure. The reaction yields were better when Pt was impregnated on the TiO2 film than when Pt was incorporated in the Ti sol. On the other hand, pure or platinized TiO2 under visible light illumination was totally inactive indicating the role of the organic dye in generating catalytically active electrons under visible light.


Dye sensitized CO2 reduction over pure and platinized TiO2
Ozcan, O.; Yukruk, F.; Akkaya, E. U.; Üner, Deniz (2007-07-01)
TiO2 thin and thick films promoted with platinum and organic sensitizers including novel perylene diimide dyes (PDI) were prepared and tested for carbon dioxide reduction with water under visible light. TiO2 films were prepared by a dip coating sol-gel technique. Pt was incorporated on TiO2 surface by wet impregnation [Pt(on).TiO2], or in the TiO2 film [Pt(in).TiO2] by adding the precursor in the sol. When tris (2,2'-bipyridyl) ruthenium(II) chloride hexahydrate was used as sensitizer, in addition to visibl...
Photovoltaic performance of bifacial dye sensitized solar cell using chemically healed binary ionic liquid electrolyte solidified with SiO2 nanoparticles
Cosar, Burak; Icli, Kerem Cagatay; Yavuz, Halil Ibrahim; Özenbaş, Ahmet Macit (2013-01-01)
In this study, we investigated the effect of electrolyte composition, photoanode thickness, and the additions of GuSCN (guanidinium thiocyanate), NMB (N-methylbenimidazole), and SiO2 on the photovoltaic performance of DSSCs (dye sensitized solar cells). A bifacial DSSC is realized and irradiated from front and rear sides. The devices give maximum photovoltaic efficiencies for 70% PMII (1-propyl-3-methyl-imidazolium iodide)/30% (EMIB(CN)(4)) (1-ethyl-3-methyl-imidazolium tetracyanoborate) electrolyte composi...
Electroforming of thin film silicon based homojunction pin diode
The recent observations of bright visible electroluminescence (EL) from electroformed thin film silicon based wide-gap alloys are further clamped down in a simpler structure. For this purpose, a standard quality, ordinary hydrogenated amorphous silicon (a-Si:H) homojunction pin diode was fabricated by plasma enhanced chemical vapor deposition. The fresh diode was characterized by temperature scanned current-voltage (I-V) and constant photocurrent measurements. The energy distribution of density of states wi...
Photon-to-carrier efficiencies of nanostructured zinc-phthalocyanine/fullerene thin films assessed by time-resolved terahertz spectroscopy
Esentürk, Okan; Lane, Paul A.; Heilweil, Edwin J. (null; 2008-01-01)
Blend and multilayer Zinc-phthalocyanine/fullerene thin films were investigated as model active layers for solar cells by Time-Resolved Terahertz Spectroscopy. A strong dependence on the blend ratio and multilayer nano-structure of the films was found
On the mechanism of photocatalytic CO2 reduction with water in the gas phase
Üner, Deniz (2012-02-12)
The mechanism of photocatalytic reduction of CO2 with H2O over Pt-TiO2 films produced by the sol-gel deposition over glass beads was investigated. The accumulation of significant amount of carbonaceous intermediate on the surface followed by deactivation indicated the rate limiting reaction is the water splitting reaction, similar to the natural photosynthetic systems. When gas phase hydrogen was allowed in the system, the carbonaceous intermediates were converted to methane at rates higher than the artific...
Citation Formats
O. Ozcan, F. Yukruk, E. U. Akkaya, and D. Üner, “Dye sensitized artificial photosynthesis in the gas phase over thin and thick TiO2 films under UV and visible light irradiation,” APPLIED CATALYSIS B-ENVIRONMENTAL, pp. 291–297, 2007, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40011.