Investigation of the effect of structure on reactivity in the titanium dioxide mediated photodecomposition of phenols and haloethers when irradiated at 350 NM in an aqueous medium

Authors

Claudia Cardona, Florida International University

Document Type

Thesis

Degree

Master of Science (MS)

Major/Program

Chemistry

First Advisor's Name

Kevin E. O'Shea

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Ramon Lopez de la Vega

Third Advisor's Name

William J. Cooper

Fourth Advisor's Name

Martin Quirke

Keywords

Water -- Purification -- Photocatalysis, Water -- Purification -- Organic compounds removal, Titanium dioxide

Date of Defense

11-2-1994

Abstract

Three studies were performed to obtain fundamental mechanistic information on the TiO₂ catalyzed photooxidations of organic substrates irradiated at 350 nm in dilute aqueous solutions under oxygenated conditions: (a) The photodecomposition of three haloethers, 2-chloroethyl ether, 4-chlorophenyl phenyl ether, and 4-bromophenyl phenyl ether, was investigated in an aqueous media at pH 7.0. (b) A comparative study of structure-reactivity was conducted on para-substituted phenols whose substituents range from electron-withdrawing to electron-donating in an aqueous media at pH 3.0. (c) The initial rates of the TiO₂ catalyzed photodegratation of phenol were studied in an aqueous media at pH 1.0, 3.0, 5.0, 7.0, 9.0, 11.0, and 13.7 and a pH effect profile was obtained and compared to the removal efficiency after four hours of irradiation. Controls were carried out throughout the three studies in the absence of light and under anoxic conditions, as well as without the semiconductor to evaluate the role of photolysis. The Langmuir-Hinshelwood model was employed in an attempt to characterize and evaluate differences in reactivity.

Identifier

FI14052573

Comments

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Recommended Citation

Cardona, Claudia, "Investigation of the effect of structure on reactivity in the titanium dioxide mediated photodecomposition of phenols and haloethers when irradiated at 350 NM in an aqueous medium" (1994). FIU Electronic Theses and Dissertations. 2044.
https://digitalcommons.fiu.edu/etd/2044