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OLS Field Name OLS Field Data
Main Title Cobalt(II) Tetrasulfophthalocyanine on Titanium Dioxide: A New Efficient Electron Relay for the Photocatalytic Formation and Depletion of Hydrogen Peroxide in Aqueous Suspensions.
Author Hong, A. P. ; Bahnemann, D. W. ; Hoffmann, M. R. ;
CORP Author California Inst. of Tech., Pasadena. W.M. Keck Engineering Lab. of Hydraulics and Water Resources.;Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Sciences Research Lab.
Year Published 1987
Report Number EPA-R-812356; EPA/600/J-87/228;
Stock Number PB88-170980
Additional Subjects Titanium dioxide ; Reprints ; Cobalt(II) tetrasulfophthalocyanine ; Hydrogen peroxide
Holdings
Library Call Number Additional Info Location Last
Modified
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Status
NTIS  PB88-170980 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 06/21/1988
Collation 11p
Abstract
The synthesis of the covalent linkage of Cobalt(II)tetrasulfophthalocyanine (Co(II)TSP) to the surface of titanium dioxide (TiO2) particles is described. Upon irradiation with light, which exceeds the bandgap energy of TiO2, Co(II)TSP is reduced to Co(I)TSP under anoxic conditions both as a dry powder and in aqueous suspension. The photochemical reduction is shown to be fully reversible in the presence of O2. Hydrogen peroxide is produced upon irradiation of an aerated aqueous suspension of the 'hybrid' catalyst, TiO2-Co(II)TSP. Formation kinetics are followed in situ with a polarographic detector; quantum yields, between 0.16 and 0.49 have been determined. The reactive photocatalytic center appears to be generated by the attachment of O2 in the open apical coordination site of the hybrid Co(II)TSP complex. Formation of Co(III)TSPO2- is enhanced by the binding of TiO- surface groups in the opposite apical position. Hydrogen peroxide is produced in a two step electron transfer from the conduction band via the Co(III) center.