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Jessie Penich,
Samir Raut
Saint Vincent College
Subject Listing - Chemistry
Advisor: Dr. Steven Gravelle
Friday, Oral Session 6, Presentation 1, Karpen Hall 035
SEMICONDUCTOR PHOTOCATALYSIS OF FERROUS IRON
The purpose of this research was to determine whether or not the oxidation rate of ferrous iron [Fe(II)] to solid iron [Fe(III)] can be increased using semiconductor photocatalysis. Many streams in western Pennsylvania are contaminated by iron due to a long history of coal mining in the area. In wetland treatment systems, a high rate of Fe(II) oxidation would allow more water to be treated and released back into the stream over a shorter period of time. The method for increasing the Fe(II) oxidation rate proposed in this research was semiconductor photocatalysis. Powdered (solid) titanium dioxide was used as the semiconductor photocatalyst for each experimental trial and the light source used was a 400 watt Xenon arc lamp. Each experimental trial was carried out in a rotating 25 mL reaction cell and small samples of solution were drawn out after regular time intervals of light exposure. The data for each experimental trial was obtained by using a UV/VIS spectrometer to generate a spectrum for each sample at each time interval. For comparison purposes, a control was performed for each experimental trial in which no photocatalyst was used. The data for each trial was analyzed by comparing the rate of decrease in the concentration peak for Fe(II) in the control spectrum to the rate of decrease of the Fe(II) concentration peak in the spectrum from the actual experiment. Several different experiments were performed to observe the behavior of Fe(II) in photocatalysis reactions. The two experiments that provided the most definitive conclusions were the photocatalyis of Fe(II) alone and the photocatalysis of Fe(II) with hydrogen peroxide. The results from these two experiments (and several others that were performed in this research) suggest that Fe(II) will not oxidize to Fe(III) during semiconductor photocatalysis. In summary, the data from this research indicates that semiconductor photocatalysis would not be an effective method for increasing the oxidation rate of Fe(II).
Advisor: Dr. Steven Gravelle, Associate Professor, Chemistry, Saint Vincent College, Latrobe, PA