Photoelectrochemistry at particulate systems. 4. Photosensitization of a TiO/sub 2/ semiconductor with a chlorophyll analogue

Journal Article · Thu Mar 27 04:00:00 EST 1986 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100398a035· OSTI ID:5814178

Kamat, P V; Chauvet, J P; Fessenden, R W

Chlorophyllin, an analogue of chlorophyll a, when adsorbed on colloidal TiO/sub 2/ can participate in the sensitization process by injecting electrons from its excited states into the conduction band of the semiconductor. Upon excitation in its absorption band, 90% of the fluorescence emission of chlorophyllin could be quenched by colloidal TiO/sub 2/. The apparent association constant for the association between colloidal TiO/sub 2/ and chlorophyllin, as measured from the fluorescence quenching data, was 2 x 10/sup 4/ M/sup -1/. Picosecond lifetime measurements gave the rate constant for the electron injection process from the excited singlet state into the conduction band of the semiconductor as 4.2 x 10/sup 9/ s/sup -1/. The net charge transfer across the sensitizer-semiconductor interface was investigated with the laser flash photolysis and time-resolved microwave absorption techniques. Analysis of the transient absorption spectrum confirmed the generation of the cation radical of chlorphyllin with a quantum yield of 0.015. 32 references, 8 figures, 1 table.

• Research Organization: Univ. of Notre Dame, IN
• OSTI ID: 5814178
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 90:7; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400 -- Electrochemistry
400500* -- Photochemistry
ABSORPTION SPECTROSCOPY
ACETONITRILE
ALCOHOLS
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
CHLOROPHYLL
COLLOIDS
COMPLEXES
COPPER COMPLEXES
DATA
DE-EXCITATION
DECOMPOSITION
DISPERSIONS
ELECTRON TRANSFER
EMISSION SPECTROSCOPY
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EQUATIONS
ETHANOL
EXPERIMENTAL DATA
FLUORESCENCE
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
LASERS
LIFETIME
LUMINESCENCE
MICROWAVE SPECTRA
NEODYMIUM LASERS
NITRILES
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PREDICTION EQUATIONS
PROTEINS
RADIATIONLESS DECAY
SOLID STATE LASERS
SPECTRA
SPECTROSCOPY
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSIENTS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS
VISIBLE SPECTRA