Photochemical conversion of solar energy. Third quarter progress report, July 1, 1975--September 30, 1975. [Iron--thionine]

Technical Report · Fri Oct 31 04:00:00 EST 1975

OSTI ID:5253047

Lichtin, N N

Quantum yield for current conversion of the totally illuminated thin layer (TI-TL) photogalvanic cell with SnO/sub 2/ anode and platinum cathode filled with an approximately saturated solution of thionine (TH/sup +/) in 50 v/v percent aq. CH/sub 3/CN is 7 percent with 80 ..mu.. electrode spacing and 15 percent with 25 ..mu.. spacing. I/sub sc/ varies linearly with light intensity up to 65 mW cm/sup -2/. Electrical output of the methylene blue element of a two element stacked TI-TL SnO/sub 2//InSnO/sub 2/ cell (80 ..mu.. spacing) with approximately saturated TH/sup +/ (in 50 v/v percent aq. CH/sub 3/CN) in the element exposed directly to light and saturated methylene blue (MB/sup +/) in the second element is the same as the output of the separated MB/sup +/ element. Deaerated TH/sup +/ and MB/sup +/ cell solutions in 50 v/v percent aq. CH/sub 3/CN degrade upon exposure to sunlight for several days. The addition of approximately 10 v/v percent of benzyl alcohol to 50 v/v percent aq. CH/sub 3/CN approximately doubles the solubility of TH/sup +/ sulfate without changing electrical output. Output from 80..mu.. TI-TL SnO/sub 2//Pt cells is unchanged when TH/sup +/ is replaced by thionine-1-sulfonic acid (TS) if the solvent is water but is reduced by approximately 95 percent with 50 v/v percent aq. CH/sub 3/CN as solvent. Lauryl sulfate in concentrations greater than 10/sup -2/ M solubilizes TH/sup +/ sulfate in water and suppresses dimerization. Such solutions produce very low electrical output. Additional kinetic characteristics of triplet excited states of TH/sup +/ and MB/sup +/ have been determined in solution in water and in 50 v/v percent aq. CH/sub 3/CN. The specific rates of oxidation of leucomethylene blue (MBH/sub 2//sup +/) and leucothionine (TH/sub 3//sup +/) by ferric sulfate are similar in these solvents. The oxidation of TH/sub 3//sup +/ by Fe(III) has been shown to proceed via a reversibly formed complex.

• Research Organization: Boston Univ., Mass. (USA). Dept. of Chemistry
• OSTI ID: 5253047
• Report Number(s): NSF/RANN/SE/AER-72-03597/A03/75/3
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505* -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
AMINES
AZINES
CHEMICAL REACTION KINETICS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
DISPERSIONS
DRUGS
ELECTROCHEMICAL CELLS
ELECTROCHEMISTRY
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HETEROCYCLIC COMPOUNDS
IRON
KINETICS
METALS
METHYLENE BLUE
MIXTURES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PERFORMANCE TESTING
PHENOTHIAZINES
PHOTOCHEMISTRY
PHOTOGALVANIC CELLS
REACTION KINETICS
RESEARCH PROGRAMS
SOLUTIONS
TESTING
THIONINE
TRANSITION ELEMENTS