Carbon dioxide photoelectrochemical

Taniguchi, I. Electrochemical and Photoelectrochemical Reduction of Carbon Dioxide 20... 

Benniston AC, Haniman A (2008) Artificial photosynthesis. Materials Today 11 26-34 Inoue T, Fujishima A, Konishi S, Honda K (1979) Photoelectrocatalytic reduction of carbon dioxide in aqueous suspensions of semiconductor powders. Nature 277 637-638 Halmann M (1978) Photoelectrochemical reduction of aqueous carbon dioxide on p-type gallium phosphide in liquid junction solar cells. Nature 275 115-116 Heminger JC, Carr R, Somorjai GA (1987) The photoassisted reaction of gaseous water and carbon dioxide adsorbed on the SrH03 (111) crystal face to form methane. Chem Phys Lett 57 100-104... 

Taniguchi, L, Electrochemical and photoelectrochemical reduction of carbon dioxide, in Modem Aspects of Electrochemistry, J. Bockris et al., Eds., Vol. 20, Kluwer, New York, 1989, p. 327. 

M. Halmann. Photoelectrochemical reduction of aqueous carbon dioxide on p-type gallium phosphide in liquid junction solar cells. Nature. 1978, 275(5676) 115-116. 

Recently, results of careful experiments were reported by Ito et a/.101 They claimed that formic acid, formaldehyde, and methanol, which had been previously reported as photoelectrochemical reduction products of carbon dioxide, were observed also by photolysis of cell materials, such as electrolytes, including 15-crown-5 ether, and epoxy resin, which has often been used as the molding material of semiconductor electrodes in aqueous solutions. Previously reported reduction products were obtained also under nitrogen with (Table 4) and without (Table 5) a p-GaP photocathode under illumination. These precise experiments under improved conditions, where no photolytic products were observed, gave the result that the main reduction product of carbon dioxide at a p-GaP photocathode in aqueous electrolytes was formic acid. Thus, many kinds of products reported in previous papers83,97,100 were suggested to be due to photolysis of cell materials. 

The results of Ito et a/.101 indicate that careful experiments including enough blank experiments are necessary in studies of photoelectrochemical reduction products of carbon dioxide because, unfortunately, the products observed to date are in very low concentrations. Purification of the carbon dioxide gas itself should also be considered, expecially in experiments in which a continuous flow of C02 gas is used. Accumulation of organics which are present as impurities in C02 gas is often observed. Purification methods for C02 gas used are given in some papers,95"97,102 but establishment of a common recommended method would be helpful. Also, it may be advisable to reexamine earlier work on C02 reduction to exclude meaningless results. In future experiments, the use of labeled 13C02 is to be recommended. 

In photoelectrochemical reduction of carbon dioxide, organic solvents and their mixtures with water have also been used. The use of organic solvents has the advantages103 that (1) competitive hydrogen formation can be suppressed and (2) the increased solubility of C02 in nonaqueous solutions28 30 has similar effects to the use of higher C02 pressures. 

Catalysis may be of interest even on Mars. The Martian atmosphere consists of 95% carbon dioxide and Breedlove et al. (2001) have presented that nickel cluster catalysts could be used in a photoelectrochemical process to split carbon dioxide, according to the reaction... 

Since this review has focused on photoelectrochemical conversions of organic compounds, it has neglected the redox reactions of simple inorganic materials like nitrogen, water, and carbon dioxide, species which have a rich photoelectrochemical history. Recent progress made with photoelectrochemical CO2 reduction signals the possibility that in the future organic feedstocks may derive from aldehydes and alcohols produced by photoelectrochemical reductions. 

Source Reprinted from I. Nakabayashi, F. Ushizaki, and K. Uosaki, A Photoelectrochemical Carbon Dioxide Fixation Spontaneous Up-Quality Conversion of Organic Compounds, in Environmental Aspects of Electrochemistry and Photoelectrochemistry, M. Tomkiewicz, H. Yoneyama, R. Haynes, and Y, Hori, eds. proceedings vol. 93-18, p. 49, Table 1, 1993. Reproduced by permission of the Electrochemical Society, Inc.)... 

Fig. 15.16. Current efficiencies for reduction of C02 to formic acid in an 0.1 M Li2COg solution at 25 1 °C at various electrodes. 1, In 2, Sn (previously anodized), 3, Sn 4, Zn 5, Pb and 6, Cd. (Reprinted with permission from I. Taniguchi, Electrochemical and Photoelectrochemical Reduction of Carbon Dioxide, in Modem Aspects of Electrochemistry, J. O M. Bockris, R. White and B. E. Conway, eds., No. 20, Fig. 1, p. 329, Plenum, 1989.)...

Fig. 15.22. Electrochemical behaviors of p-type photoex-cited semiconductors and Mg electrodes in C02-satu-rated acetonitrile solution with 50 mM of benzyl chloride. (Reprinted from H. Ueda, K. Nakabayashi, Z. Ushizaki, and K. Uosaki, A Photoelectrochemical Fixation of Carbon Dioxide. Spontaneous Up Quality Conversion of Organic Compound, Cherrt. Lett. 190 1748, Fig. 2, 1993. Reproduced with permission of The Chemical Society of Japan.)...

Ikeda S, Yamamoto A, Noda H, Maeda M, Ito K. Influence of surface treatment of the p-GaP photocathode on the photoelectrochemical reduction of carbon dioxide. Bull Chem Soc Jpn 1993 66 2473-7. 

A p-type silicon (p-Si) electrode modified with copper particles (particulate-Cu/p-Si) was applied to photoelectrochemical (PEC) reduction of carbon dioxide (CO2) in acetonitrile electrolyte solutions with and without 3.0 M HjO. The particulate-Cu/p-Si electrode generated high photovoltages of 0.50 to 0.75 V, and produced methane, ethylene, etc., under addition of 3.0 M HjO, similar to a Cu metal electrode, indicating that the particulate-Cu/p-Si electrode acted as an efficient electrode for the PEC reduction of CO2 in non-aqueous solutions. 

PHOTOELECTROCHEMICAL REDUCTION OF CARBON PIQXIDEFUSING SEMICONDUCTOR ELECTRODES. Several different strategies for carbon dioxide reduction on semiconductors electrodes have been used to produce CO, formic acid, or even methanol (lA) These include ... 

In an effort to overcome the limitations of electrochemical and photoelectrochemical cathodic reduction of carbon dioxide, and to draw upon insights of hydrogen insertion reactions studied in homogeneous... 

Several etching procedures were attempted for p-CdTe for the photoelectrochemical reduction of carbon dioxide. Etching with dilute thiosulfite or bromine in methanol did not result in better photocurrent-potential relationship. Hence, it was concluded that etching with aqua regia followed by rinsing with water is the best surface treatment for the photoelectrochemical reduction of carbon dioxide. All the impedance results described below were recorded using this surface in contact with electrolyte. 

E ins BR, Robertson PKJ, Murphy EP, Woods E, Irvine JTS Factors affecting the photoelectrochemical fixation of carbon dioxide with semiconductor colloids. J Photochem Photobiol A Chem 1998, 118(1) 31—40. 

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