GEOC 23 |
| The photocatalytic activity of clays has been reported in solution, but few studies evaluate the mechanism(s) controlling the generation of radicals. To date, few studies have addressed the mechanism(s) by which the incidence of light in clay minerals suspensions alters the degradation of organic compounds. Related work reporting the effectiveness of Anatase TiO2 embedded at the clay interlayer for catalyzing toluene oxidation in air was higher than in the presence of commercial TiO2 (Degussa P25). (Kibanova et al.). In this manuscript we study the kinetics and mechanism of photodegradation of methylene blue. The photocatalytic performance of expandable (e.g., nontronite) and non-expandable (e.g., kaolinite) clays is evaluated using as probes colored-analytes. We discuss the photocatalytic properties as affected by 1) the presence of structural TiO2 and 2) the amounts and redox-oxidation state of structural Fe on the generation of radical species in suspension. References Kibanova D, Trejo M, Destaillats H, Cervini-Silva J. Synthesis of Clay-TiO2 Nanocomposites with Photocatalytic Activity for the Degradation of Air Pollutants. Appl. Clay Sci. |
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Clay Minerals and Health
1:30 PM-5:10 PM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 213, Oral
Division of Geochemistry |