The photo-reactivity of titanium dioxide
Date
2022
Authors
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Publisher
University of Delaware
Abstract
Photocatalysts have a wide range of applications from energy conversion to water purification. Titanium dioxide (TiO2) is heavily studied for its photocatalytic activity and use as a white pigment. The desired photo-reactivity of TiO2 is dependent on its application, i.e. consumers do not want highly reactive white paint that degrades quickly. The complete understanding of TiO2 and its surface modifications' mechanisms when it is excited are vital for designing the photocatalyst for its application. Transient absorption spectroscopy is used throughout this entire work to probe the electronic transitions of the systems. Time-correlated single photon counting and photoelectrochemistry are also used to characterize the samples. Anatase TiO2 nanoparticle colloids averaging 11~nm in size were synthesized for the use in Chapters 3 & 4. Tetragonal zirconium dioxide nanoparticles were also synthesized. Controlled silicon dioxide patches were synthesized on rutile TiO2 as standards used in Chapters 5. In this work, the mechanism behind three different applications of TiO2 are investigated. Firstly, the possibility of the isomerization inhibition of p-methyl red bound to TiO2 is shown. Next, the enhancement of TiO2's photo-degradation properties by extending its absorption spectrum into the visible range were investigated. Lastly, the inhibition of TiO2's photoactivity by insulating coatings was studied.
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Keywords
Photo-degradation, Photoactivity, Photocatalysts, Titanium dioxide