Sensitization of titanium dioxide and strontium titanate electrodes by ruthenium(II) tris(2,2'-bipyridine-4,4'-dicarboxylic acid) and zinc tetrakis(4-carboxyphenyl)porphyrin: an evaluation of sensitization efficiency for component photoelectrodes in a multipanel device
The utility of polycrystalline anatase TiO/sub 2/ and SrTiO/sub 3/ semiconductor electrodes sensitized by ruthenium(II) tris(2,2'-bipyridine-4,4'-dicarboxylic acid) (1) and by zinc tetrakis(4-carboxyphenyl)porphyrin (2) as component photoelectrodes in a multipanel array has been evaluated. The efficiency for photocurrent generation of a single sensitized electrode is decreased as the sensitizer loading on the surface is increased beyond monolayer coverage. Power curves for both sensitizers were obtained in aqueous solutions of potassium iodide, hydroquinone, hydroquinonesulfonate (potassium salt), durohydroquinone, and potassium ferrocyanide as electron donors. From stability and efficiency considerations, hydroquinone is the most appropriate electron donor among this group. The maximum quantum efficiency attained on the metal oxide coated electrodes described herein for monochromatic excitation of 1 was 41% on TiO/sub 2/ (surface coverage 3.0 x 10/sup -10/ mol/cm/sup 2/) and 57% on SrTiO/sub 3/ (surface coverage 5.9 x 10/sup -11/ mol/cm/sup 2/). With 2 at 420 nm a maximum quantum efficiency on TiO/sub 2/ was 9.5% (surface coverage 1.7 x 10/sup -10/ mol/cm/sup 2/) and on SrTiO/sub 3/ was 27% (surface coverage 5.0 x 10/sup -12/ mol/cm/sup 2/). Better efficiencies were observed with adsorbed than with chemically bonded 1. The quantitative reproducibility of the observed photocurrents was a sensitive function of the preparation and porosity of the metal oxide surface. Porous TiO/sub 2/ gave better photoresponse than photodoped SrItO/sub 3/ as a photosensitized electrode. Despite these relatively high quantum efficiencies, the steady-state photocurrents produced on these sensitized electrodes were too low for practical operation in a multipanel device.
- Research Organization:
- Univ. of Texas, Austin (USA)
- OSTI ID:
- 5024694
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 92:7
- Country of Publication:
- United States
- Language:
- English
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ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
BIPYRIDINES
PHOTOCHEMICAL REACTIONS
PHOTOCURRENTS
CARBOXYLIC ACIDS
PORPHYRINS
RUTHENIUM COMPLEXES
STRONTIUM TITANATES
TITANIUM OXIDES
ZINC COMPLEXES
ELECTRODES
EXPERIMENTAL DATA
QUANTUM EFFICIENCY
SEMICONDUCTOR MATERIALS
ALKALINE EARTH METAL COMPOUNDS
AZINES
CHALCOGENIDES
CHEMICAL REACTIONS
COMPLEXES
CURRENTS
DATA
EFFICIENCY
ELECTRIC CURRENTS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
MATERIALS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PYRIDINES
STRONTIUM COMPOUNDS
TITANATES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS
400500* - Photochemistry
360204 - Ceramics
Cermets
& Refractories- Physical Properties