TiO2 photocatalyst has been very successful in mineralizing aquatic organic pollutants because of the strong oxidation potential of its valence band holes. A study on the photocatalytic degradation reactions of aquatic NH3, alkylamines, and alkylammoniums using pure and surface-modified TiO2 was carried out. By using TiO2 deposited with nano-Pt particles, NH3 was oxidized selectively to N2. While the pure TiO2 almost quantitatively transformed ammonia into nitrite and nitrate, Pt/TiO2 converted NH3 into N2 with reducing the total nitrogen concentration in the suspension. The Pt surface stabilized intermediate NHx species and facilitated their recombination into dinitrogen. The photocatalytic method converted NH3 to N2 in a single step. The H-atom abstraction by OH radicals initiated successive demethylation processes to generate tri-, di-, and monomethylammonium/amine as an intermediate and NH3/NH4+ as a final product. The OH radical behaviors and the product distribution were closely related and the reaction with OH radicals took place on the TiO2 surface and in the solution bulk. Results of the study of tetramethylammonium (TMA, (CH3)4N+) ions in water using both naked-TiO2 and fluorinated-TiO2 were elucidated. This is an abstract of a paper presented at the 228th ACS National Meeting (Philadelphia, PA 8/22-26/2004).
|Number of pages
|ACS, Division of Environmental Chemistry - Preprints of Extended Abstracts
|Published - 2004
|228th ACS National Meeting - Philadelphia, PA, United States
Duration: 2004 Aug 22 → 2004 Aug 26
ASJC Scopus subject areas
- General Energy