Titanium dioxide aerogels as photocatalysts for indoor air decontamination.

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dc.contributor.advisorLobban, Lance L.,en_US
dc.contributor.authorDreyer, Martina Irmgard.en_US
dc.date.accessioned2013-08-16T12:18:30Z
dc.date.available2013-08-16T12:18:30Z
dc.date.issued2002en_US
dc.description.abstractReducing air pollution, specifically volatile organic compounds, has become an increasing concern for the public, environmental protection organizations, and governmental agencies. One method for destroying air contaminants that can meet desired characteristics such as working at ambient conditions (e.g. room temperature, atmospheric pressure, and use of oxygen from air as oxidizing agent) is photocatalytic oxidation. Anatase titanium dioxide has shown to be the most promising active photocatalyst for decomposition of air contaminants such as carbohydrates, volatile organic compounds, and odorants to harmless products like water and carbon dioxide. This work presents some new forms of photocatalysts that could significantly improve the available technology for photocatalytic degradation of air contaminants.en_US
dc.description.abstractPure low density as well as ultra-low density titanium dioxide aerogels have been synthesized in our labs and several tests of photocatalytic activity of the TiO2 aerogel catalysts have been carried out using methane, ethane, ethylene, and acetone as air contaminants. The same tests have been carried out on Degussa P25, a TiO2 containing 70% anatase and 30% rutile. The effectiveness of the aerogels in removing the here-applied contaminants is compared to the commercially available P25 on several different bases (mass, illuminated cell window area, and UV accessible catalyst volume and catalyst surface area). The superiority of the aerogel was attributed to a larger fraction of interior surface, to the high porosity resulting in a higher accessibility of reaction sites, as well as to a higher UV light penetration into the catalyst bulk. UV transmittance measurements of dispersed catalyst powders in a UV-transparent agar gel showed that all aerogel samples demonstrated a higher UV light transmittance compared to the nonporous Degussa P25, thus allowing for UV light to penetrate five times deeper through an aerogel material compared to Degussa P25.en_US
dc.description.abstractEthylene photooxidation under humid conditions showed a decrease in photocatalytic activity of all tested catalysts. But even at a relative humidity close to 50%, the aerogel photocatalyst retained good photocatalytic activity.en_US
dc.description.abstractThe adsorption equilibrium constants and the reaction rate constants for methane, ethane, ethylene, and acetone were determined from initial rate data using a Langmuir-Hinshelwood model. The obtained models provided satisfactory fits to the experimental data.en_US
dc.description.abstractThe aerogels' activity was further enhanced by thermal treatment and by the deposition of platinum. A platinum content of 1.2wt% increased the ethylene oxidation reaction rate constant by 35% for the Degussa P25 and by 11% for the aerogel T36.en_US
dc.format.extentxxix, 356 leaves :en_US
dc.identifier.urihttp://hdl.handle.net/11244/430
dc.noteMajor Professor: Lance L. Lobban.en_US
dc.noteSource: Dissertation Abstracts International, Volume: 63-01, Section: B, page: 0387.en_US
dc.subjectEngineering, Chemical.en_US
dc.subjectIndoor air pollution.en_US
dc.subjectTitanium dioxide.en_US
dc.subjectAerogels.en_US
dc.subjectEngineering, Civil.en_US
dc.thesis.degreePh.D.en_US
dc.thesis.degreeDisciplineSchool of Chemical, Biological and Materials Engineeringen_US
dc.titleTitanium dioxide aerogels as photocatalysts for indoor air decontamination.en_US
dc.typeThesisen_US
ou.groupCollege of Engineering::School of Chemical, Biological and Materials Engineering
ou.identifier(UMI)AAI3040846en_US

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