Influence of Perchloric Acid and Cerous Perchlorate upon the Photochemical Oxidation of Cerous to Ceric Perchlorate in Dilute Aqueous Perchloric Acid

Heidt, Lawrence J.; McMillan, Alan F.

doi:10.1021/ja01637a028

Cited by 53 publications

(13 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The maximum theoretical efficiency for NOC1 drops to 6.8% over the entire solar spectrum, about 1400 w/m 2 , the decrease being due to its lack of absorption or lack of photodecomposition at wave lengths longer than about 6500 A. Sensitized photolysis can sometimes be used to increase the efficiency of a system by extending the wavelength range over which solar energy is absorbed. This is particularly important in such cases as the photodecomposition of water by the ultraviolet absorption of cerium and iron solutions (11). We suggest that it may be possible to apply photosensitization to increase the theoretical efficiency of the NOC1 photolysis system.…”

Section: E W = W Max /W Smentioning

confidence: 99%

“…The stability of hydrogen-oxygen mixtures (under appropriate conditions) also add to the desirability of having a regenerative fuel cell based on the photodecomposition of water. Unfortunately, although the photosensitized decomposition of water with a ceric-cerous system and a ferric-ferrous system has been demonstrated to occur at 2537 A, the amount of photolysis from the solar spectrum is negligible (11).…”

Section: Photoregenerative Fuel Cellsmentioning

confidence: 99%

See 1 more Smart Citation

Photochemistry and Space Power Generation

Pitts

1961

ARS Journal

View full text Add to dashboard Cite

Some of the fundamental aspects of photochemistry are reviewed with reference to the direct use of solar radiation for the initiation of chemical reactions from which power can be generated. Photoregenerative fuel cells and photogalvanic cells are denned, and they are discussed in terms of criteria of usefulness, calculations of theoretical efficiencies and limiting factors. The nitrosyl chloride system is used as an example to illustrate the theoretical calculations of efficiency and maximum power available from a solar regenerative fuel cell. The development of a fuel cell operating on nitric oxide and chlorine is reported. The competitive process of nitric oxide-chlorine recombination following the photodecomposition of nitrosyl chloride is also considered. The problem of direct energy storage in photogalvanic batteries is discussed, and some areas of research for the development of photogalvanic cells are recommended.

show abstract

Section: E W = W Max /W Smentioning

confidence: 99%

Section: Photoregenerative Fuel Cellsmentioning

confidence: 99%

Photochemistry and Space Power Generation

Pitts

1961

ARS Journal

View full text Add to dashboard Cite

show abstract

“…Kiwi and Grätzel [6] succeeded to increase the oxygen yield by adding certain redox catalysts (Pt0 2 or Ir0 2 ). They observed for the formation of oxygen a rate of k = 3 X 10-5 mol • dm- 3 • h~i and for the eerie ion reduction, k = 1.2 x 10-4 mol • dm- 3 • h~i.…”

Section: Introductionmentioning

confidence: 99%

Photocatalytic Splitting of Liquid Water by n-TiO₂ Suspension

Vonach

Getoff

1981

Zeitschrift Für Naturforschung A

View full text Add to dashboard Cite

By illumination (A >300 nm) of a suspension of n-Ti02 (grain size 5^0.06 mm, 3 to 15 mg/ml) in aqueous acid solutions, containing 10 -3 mol • dm -3 Ce 4+ -ions an enhanced evolution of oxygen is observed. Its yield is dependent on the amount of TiC>2 in the suspension and on the temperature. Using n-TiC>2 suspended in diluted sulfuric acid, hydrogen and oxygen were produced in a ratio of about 2: 1. In both systems n-TiC>2 is acting as an efficient electron donor. For the explanation of the processes probable reaction mechanisms are proposed.

show abstract

“…photoreduction ͉ organometallic ͉ ultrafast spectroscopy ͉ time-resolved EXAFS ͉ photodissociation T he photochemistry of transition metal trisoxalato complexes (1) has been studied extensively (2,3), not only because of their wide application in areas such as chemical actinometry (4), radical polymerization reaction initiation (5), degradation of organic pollutants (6) and as solar energy media (7), but also because they have served as textbook models for electron transfer (ET) (8,9) and stereochemistry (10). For a long period, transition metal trisoxalato complexes were thought to undergo exclusively intramolecular ET from the oxalate group to the metal, ligand to metal, immediately after irradiation inside the charge-transfer band.…”

mentioning

confidence: 99%

Photochemistry and electron-transfer mechanism of transition metal oxalato complexes excited in the charge transfer band

Chen

Zhang

Tomov

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The photoredox reaction of trisoxalato cobaltate (III) has been studied by means of ultrafast extended x-ray absorption fine structure and optical transient spectroscopy after excitation in the charge-transfer band with 267-nm femtosecond pulses. The Co-O transient bond length changes and the optical spectra and kinetics have been measured and compared with those of ferrioxalate. Data presented here strongly suggest that both of these metal oxalato complexes operate under similar photoredox reaction mechanisms where the primary reaction involves the dissociation of a metal-oxygen bond. These results also indicate that excitation in the charge-transfer band is not a sufficient condition for the intramolecular electron transfer to be the dominant photochemistry reaction mechanism.photoreduction ͉ organometallic ͉ ultrafast spectroscopy ͉ time-resolved EXAFS ͉ photodissociation T he photochemistry of transition metal trisoxalato complexes (1) has been studied extensively (2, 3), not only because of their wide application in areas such as chemical actinometry (4), radical polymerization reaction initiation (5), degradation of organic pollutants (6) and as solar energy media (7), but also because they have served as textbook models for electron transfer (ET) (8, 9) and stereochemistry (10). For a long period, transition metal trisoxalato complexes were thought to undergo exclusively intramolecular ET from the oxalate group to the metal, ligand to metal, immediately after irradiation inside the charge-transfer band. This hypothesis was based on continuous wave, flash photolysis (11-14) and nanosecond laser spectroscopic experimental results (15) in both aqueous and nonaqueous (16, 17) solutions. However, the proposed intramolecular ET process was thought to occur in the picosecond range, which could not be time-resolved with the methods that were then used. Owing to the lack of direct experimental support, such as transient absorption spectra or the observation of transient structural changes, intermolecular and intramolecular ET remained speculative. Is excitation in the charge-transfer band a sufficient condition for intramolecular electron transfer? What is the photochemical behavior difference between chargetransfer (CT) and ligand-field (LF) bands and why? The development of ultrafast spectroscopy, especially ultrafast x-ray spectroscopy (18-22), allow us to reevaluate the photochemical mechanism of transition metal complexes. Previously, we performed static extended x-ray absorption fine structure (EXAFS) spectroscopic experiments that revealed the structures of only the initial and final product in the photolysis of CBr 4 without any attempt, as clearly stated, to measure the structure of any intermediate product (23). This was in contrast to a report (24) that suggested that time-resolved EXAFS studies were performed and CBr 4 photolysis intermediates in solution were not observed. In fact, the final Br 3 CCBr 3 product detected and measured (23) can only be formed by CBr 3 radical recombination. It is also to...

show abstract

Influence of Perchloric Acid and Cerous Perchlorate upon the Photochemical Oxidation of Cerous to Ceric Perchlorate in Dilute Aqueous Perchloric Acid

Cited by 53 publications

References 0 publications

Photochemistry and Space Power Generation

Photochemistry and Space Power Generation

Photocatalytic Splitting of Liquid Water by n-TiO₂ Suspension

Photochemistry and electron-transfer mechanism of transition metal oxalato complexes excited in the charge transfer band

Contact Info

Product

Resources

About

Influence of Perchloric Acid and Cerous Perchlorate upon the Photochemical Oxidation of Cerous to Ceric Perchlorate in Dilute Aqueous Perchloric Acid

Cited by 53 publications

References 0 publications

Photochemistry and Space Power Generation

Photochemistry and Space Power Generation

Photocatalytic Splitting of Liquid Water by n-TiO2 Suspension

Photochemistry and electron-transfer mechanism of transition metal oxalato complexes excited in the charge transfer band

Contact Info

Product

Resources

About

Photocatalytic Splitting of Liquid Water by n-TiO₂ Suspension