Photochemical conversion of solar energy. Semi-annual progress report, 1 January--30 June 1976. [Iron-thionine]

Technical Report · Thu Oct 28 04:00:00 EDT 1976

OSTI ID:7257675

Lichtin, N N

Ohmic resistance of the SnO/sub 2/ electrode of the iron-thionine (TH+) TI-TL SnO/sub 2//Pt cell was shown to contribute to current losses. Voc of the cell varies linearly with log (white light intensity) up to at least 60 mW/sq cm while Isc varied linearly with light intensity up to approximately equal to 30 mW/sq cm. Cyclic voltammetry showed that SnO/sub 2/ is selective for the TH(+)/TH3(+) couple in 50v/v% aq. CH/sub 3/CN. EFB and charge density of SnO/sub 2/ electrodes are approximately equal to 0.0V vs. SCE and 10 to the 19th power - 10 to the 20th power/cc, respectively. Thin TiO/sub 2/ layers reduced with H/sub 2/ at 600C provide a promising selective anode for the iron-TH(+) cell. Cd/sub 2/SnO/sub 4/ deposited on quartz is a promising transparent cathode. Reduction with H/sub 2/ at 400C improved power output characteristics of the SnO/sub 2/ electrode by more than 50% and increased the reversibility of the dye couple at this electrode. Toluidine blue 0 shows photogalvanic activity comparable to that of TH(+). Substantial sensitization to the blue of the photogalvanic activity of TH(+), methylene blue and azure A have been demonstrated for a number of dyes, of which Rhodamine 6G is the most effective sensitizer. Sensitization is more than twice as effective with 25 micrometers as with 80 micrometers electrode separation. Power output in white light has been increased by as much as 5.8 fold by sensitization. The dependence of the composition and kinetics of decay of the photostationary state of acidic iron-TH(+) solutions on solvent anions and initial concentrations of solutes has been measured and correlated with rates of elementary reactions. Sensitization increases the photostationary concentration of leucothiazine.

• Research Organization: Boston Univ., MA (USA). Dept. of Chemistry
• OSTI ID: 7257675
• Report Number(s): PB-262450; NSF/RANN/SE/AER-72/03579/A05/76/2
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505* -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
AMINES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
CONVERSION
DYES
ELECTROCHEMICAL CELLS
ELECTRODES
ELECTROLYTIC CELLS
ELEMENTS
ENERGY CONVERSION
HETEROCYCLIC COMPOUNDS
IRON
METALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMISTRY
PHOTOGALVANIC CELLS
PLATINUM
PLATINUM METALS
REAGENTS
REDOX REACTIONS
RESEARCH PROGRAMS
SENSITIZERS
SOLAR ENERGY CONVERSION
THIONINE
TIN COMPOUNDS
TIN OXIDES
TRANSITION ELEMENTS