Oxidative Strength of Visible-Light Activated Nanophase Titanium Oxide Materials
An emerging class of pollutants have materialized in recent years that cannot be removed efficiently by conventional water treatment processes. Advanced oxidation technologies, including TiO2 photocatlysis have the potential for degrading these compounds to less hazardous byproducts or mineralizing them to carbon dioxide, water, and other inorganic components. The objective of this research was to compare the oxidative strength of nitrogen doped versus un-doped titanium oxides under visible and ultraviolet light. The degradation of substituted phenolic compounds was monitored in aqueous suspensions of titanium oxides that were irradiated with light of wavelengths in the visible (? > 400 nm) and ultraviolet region (? > 324 nm), at pH 3 and 11. Degradation was measured by monitoring the changes in the UV-VIS absorbance at characteristic wavelengths. The rates of phenol oxidation increased with increasing acid-base ionization constants values (pKa) for Nitrogen doped TiO2. Pure TiO2 had relatively faster rates of degradation than its nitrogen-doped counterpart.
School:
Columbia University
Department:
Environmental Chemistry
Research Advisor:
Timothy Strathmann
Department of Research Advisor:
Environmental Engineering and Science
Year of Publication:
2005